Process for distillation of crude isocyanate concentrates

ABSTRACT

A process is described for the separation and recovery of isocyanate monomers from isocyanate concentrates which leaves a residue which is liquid and burnable. The process for the separation and recovery of isocyanate monomers from isocyanate concentrates formed in the production of isocyanates and comprising a volatile isocyanate monomer and by-products comprises the steps of: 
     (A) preparing a mixture comprising 
     (A-1) the isocyanate concentrate; and 
     (A-2) an oil solution comprising; 
     (A-2-a) a major amount of hydrocarbon oil, and 
     (A-2-b) a minor amount of at least one carboxylic ester obtained by reacting 
     (A-2-b-1) at least one substituted succinic acylating agent with 
     (A-2-b-2) at least one alcohol of the general formula 
     
         R.sub.3 (OH).sub.M                                         (I) 
    
      wherein R 3  is a monovalent or polyvalent organic group joined to the OH groups through carbon bonds, and m is an integer of from 1 to about 10; and 
     (B) heating the mixture to an elevated temperature whereby isocyanate monomer is distilled and recovered leaving a liquid residue. 
     The presence of the oil solution in the mixture facilitates the distillation of the isocyanate concentrate, generally improves the yield of distilled isocyanate monomer, results in a residue which is liquid and easily removed from the distillation apparatus, and the liquid residue can be burned without difficulty.

This is a continuation of copending application(s) Ser. No. 07/319,011filed on Mar. 3, 1989.

FIELD OF THE INVENTION

This invention relates to a process for recovering isocyanates fromcrude isocyanate concentrates. In particular, this invention relates toa process for separating and recovering isocyanate monomers from crudeisocyanate concentrates formed from the production of isocyanates andcomprising a volatile isocyanate monomer and by-products.

BACKGROUND OF THE INVENTION

Various methods for preparing isocyanates have been reported in theliterature. An important commercial method for preparing isocyanatesinvolves the phosgenation of primary amines. Isocyanates also can beprepared utilizing the Curtius rearrangement of an acid azide in aneutral solvent. The Curtius reaction is used primarily for thepreparation of short chain aliphatic diisocyanates and unsaturatedisocyanates. The Hofmann rearrangement of amides to form isocyanates isuseful for preparing isocyanates which do not react with water since anaqueous medium is required. Another, less frequently used reaction, isthe Lossen rearrangement of hydroxamic acids. The process can beexemplified by the preparation of octamethylene diisocyanate from thedisodium salt of sebacic dihydroxamic acid. Other procedures forpreparing isocyanate compounds are described in Saunders and Frisch:Polyurethanes:Chemistry and Technology I. Chemistry, Part I, pages17-28, Interscience Publishers, New York, N.Y., 1962.

Considerable quantities of relatively high molecular weight,cross-linked, by-products are formed in these processes, particularly inthe phosgene process. Generally, the by-products are obtained in theform of a tar-like, non-distillable residue during and after thedistillation of the crude isocyanate concentrate solutions obtained inthe phosgenation of amines.

In a commercial method for preparing diisocyanates, an amine solution ismixed with phosgene at a low or moderate temperature. The resultingslurry is then treated with additional phosgene at a higher temperaturesuch as from about 120°-150° C., and the product is obtained bydistillation. During the distillation of the concentrate, relativelyhigh molecular weight insoluble products containing uretdione,isocyanurate, carbodimide, uretone imine, urea and biuret groups areformed under the conditions of the distillation. The residue whichremains after distillation are slag-like materials which are generallysubstantially insoluble in conventional solvents, and althoughconsiderable effort has been expended in developing uses for theresidues, a vast majority of the distillation residues are either dumpedor burned in furnaces with considerable difficulty. In those instanceswhere the distillation residues have been burned, the deposits of firmlyadhering, substantially non-flammable tarry masses often accumulate inthe combustion chamber, and some of these tarry masses have decomposedexplosively at temperatures above about 500° C.

U.S. Pat. No. 4,251,401 describes the preparation of stable suspensionsof substantially monomer-free, insoluble, powdered tolylene diisocyanatedistillation residues in polyhydroxy compounds. The suspensions arereported as being useful as the polyol component in the production ofpolyurethane plastics including foamed polyurethane plastics. U.S. Pat.No. 4,297,456 describes the process for working up the distillationresidue obtained in the commercial production of tolylene diisocyanateby grinding, and optionally, accompanied and/or followed by chemicalmodification reactions. The finely divided powder is reported as beinguseful as a reactant filler in the production of a variety of plastics.

Other processes have been proposed for handling and disposing isocyanatedistillation residues. In Col. 1 of U.S. Pat. No. 4,297,456, a number ofpatents and publications are described which relate to dissolving TDIdistillation residues.

SUMMARY OF THE INVENTION

A process is described for the separation and recovery of isocyanatemonomers from isocyanate concentrates which leaves a residue which isliquid and burnable. The process for the separation and recovery ofisocyanate monomers from isocyanate concentrates formed in theproduction of isocyanates and comprising a volatile isocyanate monomerand by-products comprises the steps of:

(A) preparing a mixture comprising

(A-1) the isocyanate concentrate; and

(A-2) an oil solution comprising;

(A-2-a) a major amount of hydrocarbon oil, and

(A-2-b) a minor amount of at least one carboxylic ester obtained byreacting

(A-2-b-1) at least one substituted succinic acylating agent with

(A-2-b-2) at least one alcohol of the general formula

    R.sub.3 (OH).sub.m                                         (I)

wherein R₃ is a monovalent or polyvalent organic group joined to the OHgroups through carbon bonds, and m is an integer of from 1 to about 10;and

(B) heating the mixture to an elevated temperature whereby isocyanatemonomer is distilled and recovered leaving a liquid residue.

In one preferred embodiment, the oil solution (A-2) also contains(A-2-c) a minor amount of at least one neutral or basic alkali metal oralkaline earth metal salt of at least one acidic organic compound.

The presence of the oil solution in the mixture facilitates thedistillation of the isocyanate concentrate, generally improves the yieldof distilled isocyanate monomer, results in a residue which is liquidand easily removed from the distillation apparatus, and the liquidresidue can be burned without difficulty.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

It has now been discovered that isocyanate monomers can be recovered inhigh purity and in improved yields from crude isocyanate concentrateswhich comprise a volatile isocyanate monomer and by-products. Ingeneral, the process involves preparing a mixture comprising the crudeisocyanate concentrate and an oil solution as described hereinafter, andheating the mixture to an elevated temperature, generally at a reducedpressure, whereby isocyanate monomer is distilled and recovered leavinga liquid residue.

The following definitions apply throughout this specification and claimsunless clearly indicated otherwise.

The number of equivalents of the acylating agent depends on the totalnumber of carboxylic functions present. In determining the number ofequivalents for the acylating agents, those carboxyl functions which arenot capable of reacting as a carboxylic acid acylating agent areexcluded. In general, however, there is one equivalent of acylatingagent for each carboxy group in these acylating agents. For example,there are two equivalents in an anhydride derived from the reaction ofone mole of olefin polymer and one mole of maleic anhydride.Conventional techniques are readily available for determining the numberof carboxyl functions (e.g., acid number, saponification number) and,thus, the number of equivalents of the acylating agent can be readilydetermined by one skilled in the art.

An equivalent weight of polyhydric alcohol is its molecular weightdivided by the total number of hydroxyl groups present in the molecule.Thus, an equivalent weight of ethylene glycol is one-half its molecularweight.

The equivalent weight of a hydroxyamine used to form the carboxylicesters (A-2-b) useful in this invention is its molecular weight dividedby the number of hydroxyl groups present, and the nitrogen atoms presentare ignored. Thus, when preparing esters from, e.g., diethanolamine, theequivalent weight is one-half the molecular weight of diethanolamine.

The terms "substituent" and "acylating agent" or "substituted succinicacylating agent" are to be given their normal meanings. For example, asubstituent is an atom or group of atoms that has replaced another atomor group in a molecule as a result of a reaction. The term acylatingagent or substituted succinic acylating agent refers to the compound perse and does not include unreacted reactants used to form the acylatingagent or substituted succinic acylating agent.

All parts and percentages are by weight, all temperatures are in degreesCelsius, and pressures are at or near atmospheric unless otherwisespecifically indicated.

(A-1) The Crude Isocyanate Concentrate.

The crude isocyanate concentrates which can be treated in accordancewith the present invention are concentrates obtained from thepreparation of isocyanates prior to distillation. The concentratescontain large amounts of the isocyanates and minor amounts ofby-products or secondary products. The process of this invention isapplicable in particular to crude concentrates obtained by reactingamines with phosgene. The amines may be aliphatic amines, cycloaliphaticamines, aromatic amines, or mixed aliphatic-aromatic amines, and theseamines may be monoamines or polyamines. In one preferred embodiment, theamines are primary amines.

The reaction between primary amines and phosgene is well known and isutilized for the commercial preparation of isocyanates. The reaction isillustrated as follows:

    R(NH.sub.2).sub.x +xCOCl.sub.2 →R(NCO).sub.x +xHCL

wherein x is an integer equal to the number of NH₂ groups present in theamine used in the reaction. For example, if the amine is a diamine(x=2), the diamine is reacted with two moles of phosgene and the productis a diisocyanale. In addition to the desired isocyanate, the productobtained contains a number of by-products including aminehydrochlorides, carbamoyl chlorides, substituted ureas, etc. It is thismixture that is referred to in the art and in this application as thecrude isocyanate concentrate.

Monomeric isocyanates including diisocyanates and triisocyanates, whichcan be present in the crude isocyanate concentrates treated inaccordance with the process of the present invention includehexamethylene diisocyanate, trimethylhexamethylene diisocyanate,naphthylene, trimethylhexamethylene diisocyanate,naphthylene-1,5-diisocyanate, tolylene-2,4-diisocyanate,tolylene-2,6-diisocyanate, mixtures of the tolylene 2,4- and2,6-diisocyanates, 2,4'- and 4,4'-diisocyanato diphenylmethane andmixtures of these, cyclohexyl isocyanate, stearyl isocyanate, phenylisocyanate, o-, m- and p-tolyl isocyanate, o-, m- and p-chlorophenylisocyanate, 3,4-dichlorophenyl isocyanate, 2,6-diisopropylphenylisocyanate, 2,6-triisocyanato-1,3,5-triisopropyl benzene, etc. Theresidue which remains after distillation of the monomer from the crudeisocyanate concentrate generally amounts to about 10% of the totalisocyanate production. The process of the present application isparticularly applicable to the distillation and recovery of tolylenediisocyanates (TDI).

(A-2) Oil Solution.

The oil solutions which are mixed with the isocyanate concentrate inaccordance with the process of the present invention comprise

(A-2-a) a major amount of oil, and

(A-2-b) a minor amount at least one carboxylic ester.

The oil solution may also contain a minor amount of

(A-2-c) at least one neutral or basic alkali metal or alkaline earthmetal salt of at least one acidic organic compound.

(A-2-a) The Hydrocarbon Oil

The hydrocarbon oil which is utilized in the preparation of the oilsolutions (A-2) of the invention may be based on natural oils, syntheticoils, or mixtures thereof. The hydrocarbon oils may be of the typegenerally known as lubricating oils or fuel oils.

Natural oils include animal oils and vegetable oils (e.g., castor oil,lard oil) as well as mineral lubricating oils such as liquid petroleumoils and solvent-treated or acid-treated mineral lubricating oils of theparaffinic, naphthenic or mixed paraffinic-naphthenic types. Oilsderived from coal or shale are also useful. Synthetic oils includehydrocarbon oils and halosubstituted hydrocarbon oils such aspolymerized and interpolymerized olefins (e.g., polybutylenes,polypropylenes, propylene-isobutylene copolymers, chlorinatedpolybutylenes, etc.); poly(1-hexenes), poly(1-octenes), poly(1-decenes),etc. and mixtures thereof; alkylbenzenes (e.g., dodecylbenzenes,tetradecylbenzenes, dinonylbenzenes, di-(2-ethylhexyl)-benzenes, etc.);polyphenyls (e.g., biphenyls, terphenyls, alkylated polyphenyls, etc.);alkylated diphenyl ethers and alkylated diphenyl sulfides and thederivatives, analogs and homologs thereof and the like.

Alkylene oxide polymers and interpolymers and derivatives thereof wherethe terminal hydroxyl groups have been modified by esterification,etherification, etc., constitute another class of known synthetic oilsthat can be used. These are exemplified by the oils prepared throughpolymerization of ethylene oxide or propylene oxide, the alkyl and arylethers of these polyoxyalkylene polymers.

Another suitable class of synthetic oils that can be used comprises theesters of dicarboxylic acids (e.g., phthalic acid, succinic acid, alkylsuccinic acids, alkenyl succinic acids, maleic acid, azelaic acid,suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic aciddimer, malonic acid, alkyl malonic acids, alkenyl malonic acids, etc.)with a variety of alcohols (e.g., butyl alcohol, hexyl alcohol, dodecylalcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycolmonoether, propylene glycol, etc.) Specific examples of these estersinclude dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate,dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctylphthalate, didecyl phthalate, dieicosyl sebacate, the 2-ethylhexyldiester of linoleic acid dimer, the complex ester formed by reacting onemole of sebacic acid with two moles of tetraethylene glycol and twomoles of 2-ethylhexanoic acid and the like.

Esters useful as synthetic oils also include those made from C₅ to C₁₂monocarboxylic acids and polyols and polyol ethers such as neopentylglycol, trimethylol propane, pentaerythritol, dipentaerythritol,tripentaerythritol, etc.

Silicon-based oils such as the polyalkyl-, polyaryl-, polyalkoxy-, orpolyaryloxy-siloxane oils and silicate oils comprise another usefulclass of synthetic lubricants (e.g., tetraethyl silicate, tetraisopropylsilicate, tetra-(2-ethylhexyl)silicate, tetra-(4-methylhexyl)silicate,tetra-(p-tert-butylphenyl)silicate, hexyl(4-methyl-2-pentoxy)disiloxane,poly(methyl)siloxanes, poly(methylphenyl)siloxanes, etc.). Othersynthetic oils include liquid esters of phosphorus-containing acids(e.g., tricresyl phosphate, trioctyl phosphate, diethyl ester of decanephosphonic acid, etc.), polymeric tetrahydrofurans and the like.

Unrefined, refined and rerefined oils, either natural or synthetic (aswell as mixtures of two or more of any of these) of the type disclosedhereinabove can be used in the present invention. Unrefined oils arethose obtained directly from a natural or synthetic source withoutfurther purification treatment. For example, a shale oil obtaineddirectly from retorting operations, a petroleum oil obtained directlyfrom primary distillation or ester oil obtained directly from anesterification process and used without further treatment would be anunrefined oil. Refined oils are similar to the unrefined oils exceptthey have been further treated in one or more purification steps toimprove one or more properties. Many such purification techniques areknown to those skilled in the art such as solvent extraction,hydrotreating, secondary distillation, acid or base extraction,filtration, percolation, etc. Rerefined oils are obtained by processessimilar to those used to obtain refined oils applied to refined oilswhich have been already used in service. Such rerefined oils are alsoknown as reclaimed, recycled, or reprocessed oils and often areadditionally processed by techniques directed to removal of spentadditives and oil breakdown products.

(A-2-b) The Carboxylic Ester.

The carboxylic esters useful in this invention are produced by reacting(A-2-b-1) at least one substituted succinic acylating agent with(A-2-b-2) at least one alcohol or phenol of the general formula

    R.sup.3 (OH).sub.m                                         (I)

wherein R³ is a monovalent or polyvalent organic group joined to the--OH groups through carbon bonds, and m is an integer of from 1 to about10. The carboxylic esters are included in the oil solutions (A-2) toprovide dispersancy.

The substituted succinic acylating agent (A-2-b-1) utilized in thepreparation of the carboxylic esters can be characterized by thepresence within its structure of two groups or moieties. The first groupor moiety is referred to hereinafter, for convenience, as the"substituent group(s)" and is derived from a polyalkene.

The polyalkene from which the substituent is derived is characterized ascontaining at least about 8 carbon atoms, and, more often, at leastabout 30 carbon atoms. In one embodiment the polyalkene has a numberaverage molecular weight of at least about 700. Number average molecularweights of from about 700 to about 5000 are preferred. In anotherpreferred embodiment, the substituent groups of the acylating agent arederived from polyalkenes which are characterized by an Mn value of about1300 to 5000 and an Mw/Mn value of about 1.5 to about 4.5.

The second group or moiety in the acylating agent is referred to hereinas the "succinic group(s)". The succinic groups are those groupscharacterized by the structure ##STR1## wherein X and X' are the same ordifferent provided at least one of X and X' is such that the substitutedsuccinic acylating agent can function as carboxylic acylating agents.That is, at least one of X and X' must be such that the substitutedacylating agent can form amides or amine salts with amino compounds, andotherwise function as a conventional carboxylic acid acylating agents.Transamidation reactions are considered, for purposes of this invention,as conventional acylating reactions.

Thus, X and/or X' is usually --OH, --O--hydrocarbyl, --O--M⁺ where M⁺represents one equivalent of a metal, ammonium or amine cation, --NH₂,--Cl, --Br, and together, X and X' can be --O-- so as to form theanhydride. The specific identity of any X or X' group which is not oneof the above is not critical so long as its presence does not preventthe remaining group from entering into acylation reactions. Preferably,however, X and X' are each such that both carboxyl functions of thesuccinic group (i.e., both --C(O)X and --C(O)X' can enter into acylationreactions.

One of the unsatisfied valences in the grouping ##STR2## of Formula IIforms a carbon-to-carbon bond with a carbon atom in the substituentgroup. While other such unsatisfied valence may be satisfied by asimilar bond with the same or different substituent group, all but thesaid one such valence is usually satisfied by hydrogen; i.e., --H.

Polyalkenes having the Mn and Mw values discussed above are known in theart and can be prepared according to conventional procedures. Forexample, some of these polyalkenes are described and exemplified in U.S.Pat. No. 4,234,435, and the disclosure of this patent relative to suchpolyalkenes is hereby incorporated by reference. Several suchpolyalkenes, especially polybutenes, are commercially available.

In one preferred embodiment, the succinic groups will normallycorrespond to the formula ##STR3## wherein R and R' are eachindependently selected from the group consisting of --OH, --Cl,--O--lower alkyl, and when taken together, R and R' are --O--. In thelatter case, the succinic group is a succinic anhydride group. All thesuccinic groups in a particular succinic acylating agent need not be thesame, but they can be the same. Preferably, the succinic groups willcorrespond to ##STR4## and mixtures of (IV(A)) and (IV(B)).

The polyalkenes from which the substituent groups are derived arehomopolymers and interpolymers of polymerizable olefin monomers of 2 toabout 16 carbon atoms; usually 2 to about 6 carbon atoms. Theinterpolymers are those in which two or more olefin monomers areinterpolymerized according to well-known conventional procedures to formpolyalkenes having units within their structure derived from each ofsaid two or more olefin monomers. Thus, "interpolymer(s)" as used hereinis inclusive of copolymers, terpolymers, tetrapolymers, and the like. Aswill be apparent to those of ordinary skill in the art, the polyalkenesfrom which the substituent groups are derived are often conventionallyreferred to as "polyolefin(s)".

The olefin monomers from which the polyalkenes are derived arepolymerizable olefin monomers characterized by the presence of one ormore ethylenically unsaturated groups (i.e., >C═C<); that is, they aremonoolefinic monomers such as ethylene, propylene, butene-1, isobutene,and octene-1 or polyolefinic monomers (usually diolefinic monomers) suchas butadiene-1,3 and isoprene.

These olefin monomers are usually polymerizable terminal olefins; thatis, olefins characterized by the presence in their structure of thegroup >C═CH₂. However, polymerizable internal olefin monomers (sometimesreferred to in the literature as medial olefins) characterized by thepresence within their structure of the group ##STR5## can also be usedto form the polyalkenes. When internal olefin monomers are employed,they normally will be employed with terminal olefins to producepolyalkenes which are interpolymers. For purposes of this invention,when a particular polymerized olefin monomer can be classified as both aterminal olefin and an internal olefin, it will be deemed to be aterminal olefin. Thus, pentadiene-1,3 (i.e., piperylene) is deemed to bea terminal olefin for purposes of this invention.

While the polyalkenes from which the substituent groups of the succinicacylating agents are derived generally are hydrocarbon groups, they cancontain nonhydrocarbon substituents such as lower alkoxy, lower alkylmercapto, hydroxy, mercapto, nitro, halo, cyano, carboalkoxy, (wherealkoxy is usually lower alkoxy), alkanoyloxy, and the like provided thenon-hydrocarbon substituents do not substantially interfere withformation of the substituted succinic acid acylating agents of thisinvention. When present, such non-hydrocarbon groups normally will notcontribute more than about 10% by weight, of the total weight of thepolyalkenes. Since the polyalkene can contain such non-hydrocarbonsubstituents, it is apparent that the olefin monomers from which thepolyalkenes are made can also contain such substituents. Normally,however, as a matter of practicality and expense, the olefin monomersand the polyalkenes will be free from non-hydrocarbon groups, exceptchloro groups which usually facilitate the formation of the substitutedsuccinic acylating agents of this invention. (As used herein, the term"lower" when used with a chemical group such as in "lower alkyl" or"lower alkoxy" is intended to describe groups having up to 7 carbonatoms).

Although the polyalkenes may include aromatic groups (especially phenylgroups and lower alkyl- and/or lower alkoxy-substituted phenyl groupssuch as para(tert-butyl)phenyl) and cycloaliphatic groups such as wouldbe obtained from polymerizable cyclic olefins or cycloaliphaticsubstituted-polymerizable acyclic olefins, the polyalkenes usually willbe free from such groups. Nevertheless, polyalkenes derived frominterpolymers of both 1,3-dienes and styrenes such as butadiene-1,3 andstyrene or para-(tert-butyl)styrene are exceptions to thisgeneralization. Again, because aromatic and cycloaliphatic groups can bepresent, the olefin monomers from which the polyalkenes are prepared cancontain aromatic and cycloaliphatic groups.

There is a general preference for aliphatic, hydrocarbon polyalkenesfree from aromatic and cycloaliphatic groups. Within this generalpreference, there is a further preference for polyalkenes which arederived from the group consisting of homopolymers and interpolymers ofterminal hydrocarbon olefins of 2 to about 16 carbon atoms. This furtherpreference is qualified by the proviso that, while interpolymers ofterminal olefins are usually preferred, interpolymers optionallycontaining up to about 40% of polymer units derived from internalolefins of up to about 16 carbon atoms are also within a preferredgroup. A more preferred class of polyalkenes are those selected from thegroup consisting of homopolymers and interpolymers of terminal olefinsof 2 to about 6 carbon atoms, more preferably 2 to 4 carbon atoms.However, another preferred class of polyalkenes are the latter morepreferred polyalkenes optionally containing up to about 25% of polymerunits derived from internal olefins of up to about 6 carbon atoms.

Specific examples of terminal and internal olefin monomers which can beused to prepare the polyalkenes according to conventional, well-knownpolymerization techniques include ethylene; propylene; butene-1;butene-2; isobutene; pentene-1; hexene-1; heptene-1; octene-1; nonene-1;decene-1; pentene-2; propylene-tetramer; diisobutylene; isobutylenetrimer; butadiene-1,2; butadiene-1,3; pentadiene-1,2; pentadiene-1,3;pentadiene-1,4; isoprene; hexadiene-1,5; 2-chloro-butadiene1,3;2-methyl-heptene-l; 3-cyclohexylbutene-l; 2-methylpentene-1; styrene;2,4-dichloro styrene; divinylbenzene; vinyl acetate; allyl alcohol;1-methyl-vinyl acetate; acrylonitrile; ethyl acrylate; methylmethacrylate; ethyl vinyl ether; and methyl vinyl ketone. Of these, thehydrocarbon polymerizable monomers are preferred and of thesehydrocarbon monomers, the terminal olefin monomers are particularlypreferred.

Specific examples of polyalkenes include polypropylenes, polybutenes,ethylene-propylene copolymers, styrene-isobutene copolymers,isobutene-butadiene-l,3 copolymers, propene-isoprene copolymers,isobutene-chloroprene copolymers, isobutene-(paramethyl)styrenecopolymers, copolymers of hexene-1 with hexadiene-1,3, copolymers ofoctene-1 with hexene-1, copolymers of heptene-1 with pentene-1,copolymers of 3-methyl-butene-l with octene-1, copolymers of3,3-dimethyl-pentene-l with hexene-1, and terpolymers of isobutene,styrene and piperylene. More specific examples of such interpolymersinclude copolymer of 95% (by weight) of isobutene with 5% (by weight) ofstyrene; terpolymer of 98% of isobutene with 1% of piperylene and 1% ofchloroprene; terpolymer of 95% of isobutene with 2% of butene-1 and 3%of hexene-1; terpolymer of 60% of isobutene with 20% of pentene-1 and20% of octene-1; copolymer of 80% of hexene-1 and 20% of heptene-1;terpolymer of 90% of isobutene with 2% of cyclohexene and 8% ofpropylene; and copolymer of 80% of ethylene and 20% of propylene. Apreferred source of polyalkenes are the poly(isobutene)s obtained bypolymerization of C₄ refinery stream having a butene content of about 35to about 75% by weight and an isobutene content of about 30 to about 60%by weight in the presence of a Lewis acid catalyst such as aluminumtrichloride or boron trifluoride. These polybutenes containpredominantly (greater than about 80% of the total repeating units) ofisobutene (isobutylene) repeating units of the configuration ##STR6##

The polyalkene from which the substituted groups are derived may becharacterized by an Mn value of from about 1300 to about 5000, and anMw/Mn value of at least about 1.5 and more generally from about 1.5 toabout 4.5 or about 1.5 to about 4.0. The abbreviation Mw is theconventional symbol representing weight average molecular weight, and Mnis the conventional symbol representing number average molecular weight.Gel permeation chromatography (GPC) is a method which provides bothweight average and number average molecular weights as well as theentire molecular weight distribution of the polymers. For purpose ofthis invention a series of fractionated polymers of isobutene,polyisobutene, is used as the calibration standard in the GPC.

The techniques for determining Mn and Mw values of polymers are wellknown and are described in numerous books and articles. For example,methods for the determination of Mn and molecular weight distribution ofpolymers is described in W. W. Yan, J. J. Kirkland and D. D. Bly,"Modern Size Exclusion Liquid Chromatographs", J. Wiley & Sons, Inc.,1979.

Obviously, preparing polyalkenes as described above which meet thevarious criteria for Mn and Mw/Mn is within the skill of the art anddoes not comprise part of the present invention. Techniques readilyapparent to those in the art include controlling polymerizationtemperatures, regulating the amount and type of polymerization initiatorand/or catalyst, employing chain terminating groups in thepolymerization procedure, and the like. Other conventional techniquessuch as stripping (including vacuum stripping) a very light end and/oroxidatively or mechanically degrading high molecular weight polyalkeneto produce lower molecular weight polyalkenes can also be used.

In preparing the substituted succinic acylating agents (A-2-b-1), one ormore of the above-described polyalkenes is reacted with one or moreacidic reactants selected from the group consisting of maleic or fumaricreactants of the general formula

    X(O)C--CH═CH--C(O)X'                                   (V)

wherein X and X' are as defined hereinbefore in Formula II. Preferablythe maleic and fumaric reactants will be one or more compoundscorresponding to the formula

    RC(O)--CH═CH--C(O)R'                                   (VI)

wherein R and R' are as previously defined in Formula III herein.Ordinarily, the maleic or fumaric reactants will be maleic acid, fumaricacid, maleic anhydride, or a mixture of two or more of these. The maleicreactants are usually preferred over the fumaric reactants because theformer are more readily available and are, in general, more readilyreacted with the polyalkenes (or derivatives thereof) to prepare thesubstituted succinic acylating agents of the present invention. Theespecially preferred reactants are maleic acid, maleic anhydride, andmixtures of these. Due to availability and ease of reaction, maleicanhydride will usually be employed.

The one or more polyalkenes and one or more maleic or fumaric reactantscan be reacted according to any of several known procedures in order toproduce the substituted succinic acylating agents useful in the presentinvention. For convenience and brevity, the term "maleic reactant" isoften used hereinafter. When used, it should be understood that the termis generic to acidic reactants selected from maleic and fumaricreactants corresponding to Formulae (V) and (VI) above including amixture of such reactants.

One procedure for preparing the substituted succinic acylating agents(A-2-b-1) is illustrated, in part, in U.S. Pat. No. 3,219,666 (Norman etal) which is expressly incorporated herein by reference for itsteachings in regard to preparing succinic acylating agents. Thisprocedure is conveniently designated as the "two-step procedure". Itinvolves first chlorinating the polyalkene until there is an average ofat least about one chloro group for each molecular weight of polyalkene.(For purposes of this invention, the molecular weight of the polyalkeneis the weight corresponding to the Mn value.) Chlorination involvesmerely contacting the polyalkene with chlorine gas until the desiredamount of chlorine is incorporated into the chlorinated polyalkene.Chlorination is generally carried out at a temperature of about 75° C.to about 125° C. If a diluent is used in the chlorination procedure, itshould be one which is not itself readily subject to furtherchlorination. Poly- and perchlorinated and/or fluorinated alkanes andbenzenes are examples of suitable diluents.

The second step in the two-step chlorination procedure is to react thechlorinated polyalkene with the maleic reactant at a temperature usuallywithin the range of about 100° C. to about 200° C. The mole ratio ofchlorinated polyalkene to maleic reactant is usually at least about1:1.3. (In this application, a mole of chlorinated polyalkene is thatweight of chlorinated polyalkene corresponding to the Mn value of theunchlorinated polyalkene.) However, a stoichiometric excess of maleicreactant can be used, for example, a mole ratio of 1:2. More than onemole of maleic reactant may react per molecule of chlorinatedpolyalkene. Because of such situations, it is better to describe theratio of chlorinated polyalkene to maleic reactant in terms ofequivalents. (An equivalent weight of chlorinated polyalkene, forpurposes of this invention, is the weight corresponding to the Mn valuedivided by the average number of chloro groups per molecule ofchlorinated polyalkene while the equivalent weight of a maleic reactantis its molecular weight.) Thus, the ratio of chlorinated polyalkene tomaleic reactant will normally be such as to provide at least about 1.3equivalents of maleic reactant for each mole of chlorinated polyalkene.Unreacted excess maleic reactant may be stripped from the reactionproduct, usually under vacuum, or reacted during a further stage of theprocess as explained below.

The resulting polyalkenyl-substituted succinic acylating agent is,optionally, again chlorinated if the desired number of succinic groupsare not present in the product. If there is present, at the time of thissubsequent chlorination, any excess maleic reactant from the secondstep, the excess will react as additional chlorine is introduced duringthe subsequent chlorination. Otherwise, additional maleic reactant isintroduced during and/or subsequent to the additional chlorination step.This technique can be repeated until the total number of succinic groupsper equivalent weight of substituent groups reaches the desired level.

Another procedure for preparing the substituted succinic acid acylatingagents (A-2-b-1) utilizes a process described in U.S. Pat. No. 3,912,764(Palmer) and U.K. Patent 1,440,219, both of which are expresslyincorporated herein by reference for their teachings in regard to thatprocess. According to that process, the polyalkene and the maleicreactant are first reacted by heating them together in a "directalkylation" procedure. When the direct alkylation step is completed,chlorine is introduced into the reaction mixture to promote reaction ofthe remaining unreacted maleic reactants. According to the patents, 0.3to 2 or more moles of maleic anhydride are used in the reaction for eachmole of olefin polymer; i.e., polyalkene. The direct alkylation step isconducted at temperatures of 180° C. to 250° C. During thechlorine-introducing stage, a temperature of 160° C. to 225° C. isemployed. In utilizing this process to prepare the substituted succinicacylating agents, it is necessary to use sufficient maleic reactant andchlorine to incorporate at least 1.3 succinic groups into the finalproduct, i.e., the substituted succinic acylating agent, for eachequivalent weight of polyalkene, i.e., reacted polyalkenyl in finalproduct.

Other processes for preparing the acylating agents (A-2-b-1) are alsodescribed in the prior art. U.S. Pat. No. 4,110,349 (Cohen) describes atwo-step process and the disclosure of U.S. Pat. No. 4,110,349 relatingto the two-step process for preparing acylating agent is herebyincorporated by reference.

One preferred process for preparing the substituted succinic acylatingagents (A-2-b-1) from the standpoint of efficiency, overall economy, andthe performance of the acylating agents thus produced, as well as theperformance of the derivatives thereof, is the so-called "one-step"process. This process is described in U.S. Pat. Nos. 3,215,707 (Rense)and 3,231,587 (Rense). Both are expressly incorporated herein byreference for their teachings in regard to that process.

Basically, the one-step process involves preparing a mixture of thepolyalkene and the maleic reactant containing the necessary amounts ofboth to provide the desired substituted succinic acylating agents. Thismeans that there must be at least 1.3 moles of maleic reactant for eachmole of polyalkene in order that there can be at least 1.3 succinicgroups for each equivalent weight of substituent groups. Chlorine isthen introduced into the mixture, usually by passing chlorine gasthrough the mixture with agitation, while maintaining a temperature ofat least about 140° C.

A variation on this process involves adding additional maleic reactantduring or subsequent to the chlorine introduction but, for reasonsexplained in U.S. Pat. Nos. 3,215,707 and 3,231,587, this variation ispresently not as preferred as the situation where all the polyalkene andall the maleic reactant are first mixed before the introduction ofchlorine.

Usually, where the polyalkene is sufficiently fluid at 140° C. andabove, there is no need to utilize an additional substantially inert,normally liquid solvent/diluent in the one-step process. However, asexplained hereinbefore, if a solvent/diluent is employed, it ispreferably one that resists chlorination. Again, the poly- andper-chlorinated and/or -fluorinated alkanes, cycloalkanes, and benzenescan be used for this purpose.

Chlorine may be introduced continuously or intermittently during theone-step process. The rate of introduction of the chlorine is notcritical although, for maximum utilization of the chlorine, the rateshould be about the same as the rate of consumption of chlorine in thecourse of the reaction. When the introduction rate of chlorine exceedsthe rate of consumption, chlorine is evolved from the reaction mixture.It is often advantageous to use a closed system, includingsuperatmospheric pressure, in order to prevent loss of chlorine andmaleic reactant so as to maximize reactant utilization.

The minimum temperature at which the reaction in the one-step processtakes place at a reasonable rate is about 140° C. Thus, the minimumtemperature at which the process is normally carried out is in theneighborhood of 140° C. The preferred temperature range is usuallybetween about 160° C. and about 220° C. Higher temperatures such as 250°C. or even higher may be used but usually with little advantage. Infact, temperatures in excess of 220° C. are often disadvantageous withrespect to preparing the particular acylated succinic compositions ofthis invention because they tend to "crack" the polyalkenes (that is,reduce their molecular weight by thermal degradation) and/or decomposethe maleic reactant. For this reason, maximum temperatures of about 200°C. to about 210° C. are normally not exceeded. The upper limit of theuseful temperature in the one-step process is determined primarily bythe decomposition point of the components in the reaction mixtureincluding the reactants and the desired products. The decompositionpoint is that temperature at which there is sufficient decomposition ofany reactant or product such as to interfere with the production of thedesired products.

In the one-step process, the molar ratio of maleic reactant to chlorineis such that there is at least about one mole of chlorine for each moleof maleic reactant to be incorporated into the product. Moreover, forpractical reasons, a slight excess, usually in the neighborhood of about5% to about 30% by weight of chlorine, is utilized in order to offsetany loss of chlorine from the reaction mixture. Larger amounts of excesschlorine may be used but do not appear to produce any beneficialresults.

As mentioned previously, in one embodiment, the molar ratio ofpolyalkene to maleic reactant is such that there are at least about 1.3moles of maleic reactant for each mole of polyalkene. This is necessaryin order that there can be at least 1.3 succinic groups per equivalentweight of substituent group in the product. Preferably, however, anexcess of maleic reactant is used. Thus, ordinarily about a 5% to about25% excess of maleic reactant will be used relative to that amountnecessary to provide the desired number of succinic groups in theproduct.

The terminology "substituted succinic acylating agent(s)" is used hereinin describing the substituted succinic acylating agents regardless ofthe process by which they are produced. Obviously, as discussed in moredetail hereinbefore, several processes are available for producing thesubstituted succinic acylating agents. On the other hand, theterminology "substituted acylating composition(s)", may be used todescribe the reaction mixtures produced by the specific preferredprocesses described in detail herein. Thus, the identity of particularsubstituted acylating compositions is dependent upon a particularprocess of manufacture. This is particularly true because, while theproducts of this invention are clearly substituted succinic acylatingagents as defined and discussed above, their structure cannot berepresented by a single specific chemical formula. In fact, mixtures ofproducts are inherently present. For purposes of brevity, theterminology "acylating reagent(s)" is often used hereafter to refer,collectively, to both the substituted succinic acylating agents and tothe substituted acylating compositions used in this invention.

The carboxylic esters (A-2-b) are those of the above-described succinicacylating agents with hydroxy compounds [R³ (OH)_(m) ] as definedearlier with respect to Formula I which may be aliphatic compounds suchas monohydric and polyhydric alcohols or aromatic compounds such asphenols and naphthols. The aromatic hydroxy compounds from which theesters may be derived are illustrated by the following specificexamples: phenol, beta-naphthol, alpha-naphthol, cresol, resorcinol,catechol, p,p'-dihydroxybiphenyl, 2-chlorophenol, 2,4-dibutylphenol,etc.

The alcohols from which the esters may be derived preferably contain upto about 40 aliphatic carbon atoms. They may be monohydric alcohols suchas methanol, ethanol, isooctanol, dodecanol, cyclohexanol,cyclopentanol, behenyl alcohol, hexatriacontanol, neopentyl alcohol,isobutyl alcohol, benzyl alcohol, beta-phenylethyl alcohol,2-methylcyclohexanol, beta-chloroethanol, monomethyl ether of ethyleneglycol, monobutyl ether of ethylene glycol, monopropyl ether ofdiethylene glycol, monododecyl ether of triethylene glycol, mono-oleateof ethylene glycol, monostearate of diethylene glycol, secpentylalcohol, tert-butyl alcohol, 5-bromo-dodecanol, nitrooctadecanol anddioleate of glycerol. The polyhydric alcohols preferably contain from 2to about 10 hydroxy groups. They are illustrated by, for example,ethylene glycol, diethylene glycol, triethylene glycol, tetraethyleneglycol, dipropylene glycol, tripropylene glycol, dibutylene glycol,tributylene glycol, and other alkylene glycols in which the alkylenegroup contains from 2 to about 8 carbon atoms. Other useful polyhydricalcohols include glycerol, monooleate of glycerol, monostearate ofglycerol, monomethyl ether of glycerol, pentaerythritol, 9,10-dihydroxystearic acid, 1,2-butanediol, 2,3-hexanediol, 2,4-hexanediol, pinacol,erythritol, arabitol, sorbitol, mannitol, 1,2-cyclo-hexanediol, andxylylene glycol.

An especially preferred class of polyhydric alcohols are those having atleast three hydroxy groups, some of which have been esterified with amonocarboxylic acid having from about 8 to about 30 carbon atoms such asoctanoic acid, oleic acid, stearic acid, linoleic acid, dodecanoic acid,or tall oil acid. Examples of such partially esterified polyhydricalcohols are the monooleate of sorbitol, distearate of sorbitol,monooleate of glycerol, monostearate of glycerol, di-dodecanoate oferythritol.

The esters (A-2-b) may also be derived from unsaturated alcohols such asallyl alcohol, cinnamyl alcohol, propargyl alcohol, 1-cyclohexen-3-ol,and oleyl alcohol. Still other classes of the alcohols capable ofyielding the esters of this invention comprises the ether-alcohols andamino-alcohols including, for example, the oxy-alkylene-, oxy-arylene-,amino-alkylene-, and amino-arylene-substituted alcohols having one ormore oxy-alkylene, amino-alkylene or amino-arylene oxyarylene groups.They are exemplified by Cellosolve, Carbitol, phenoxy-ethanol,mono(heptylphenyl-oxypropylene)-substituted glycerol, poly(styreneoxide), aminoethanol, 3-amino ethylpentanol, di(hydroxyethyl) amine,p-aminophenol, tri(hydroxypropyl)amine, N-hydroxyethyl ethylene diamine,N,N,N',N'-tetrahydroxytrimethylene diamine, and the like. For the mostpart, the etheralcohols having up to about 150 oxy-alkylene groups inwhich the alkylene group contains from 1 to about 8 carbon atoms arepreferred.

The esters may be diesters of succinic acids or acidic esters, i.e.,partially esterified succinic acids; as well as partially esterifiedpolyhydric alcohols or phenols, i.e., esters having free alcoholic orphenolic hydroxyl groups. Mixtures of the above-illustrated esterslikewise are contemplated within the scope of this invention.

A suitable class of esters for use in this invention are those diestersof succinic acid and an alcohol having up to about 9 aliphatic carbonatoms and having at least one substituent selected from the classconsisting of amino and carboxy groups wherein the hydrocarbonsubstituent of the succinic acid is a polymerized butene substituenthaving a number average molecular weight of from about 700 to about5,000.

The esters (A-2-b) may be prepared by one of several known methods. Themethod which is preferred because of convenience and the superiorproperties of the esters it produces, involves the reaction of asuitable alcohol or phenol with a substantially hydrocarbon-substitutedsuccinic anhydride. The esterification is usually carried out at atemperature above about 100° C., preferably between 150° C. and 300° C.The water formed as a by-product is removed by distillation as theesterification proceeds.

In most cases the carboxylic esters are a mixture of esters, the precisechemical composition and the relative proportions of which in theproduct are difficult to determine. Consequently, the product of suchreaction is best described in terms of the process by which it isformed.

A modification of the above process involves the replacement of thesubstituted succinic anhydride with the corresponding succinic acid.However, succinic acids readily undergo dehydration at temperaturesabove about 100° C. and are thus converted to their anhydrides which arethen esterified by the reaction with the alcohol reactant. In thisregard, succinic acids appear to be the substantial equivalent of theiranhydrides in the process.

The relative proportions of the succinic reactant and the hydroxyreactant which are to be used depend to a large measure upon the type ofthe product desired and the number of hydroxyl groups present in themolecule of the hydroxy reactant. For instance, the formation of a halfester of a succinic acid, i.e., one in which only one of the two acidgroups is esterified, involves the use of one mole of a monohydricalcohol for each mole of the substituted succinic acid reactant, whereasthe formation of a diester of a succinic acid involves the use of twomoles of the alcohol for each mole of the acid. On the other hand, onemole of a hexahydric alcohol may combine with as many as six moles of asuccinic acid to form an ester in which each of the six hydroxyl groupsof the alcohol is esterified with one of the two acid groups of thesuccinic acid. Thus, the maximum proportion of the succinic acid to beused with a polyhydric alcohol is determined by the number of hydroxylgroups present in the molecule of the hydroxy reactant. In oneembodiment, esters obtained by the reaction of equimolar amounts of thesuccinic acid reactant and hydroxy reactant are preferred.

In some instances it is advantageous to carry out the esterification inthe presence of a catalyst such as sulfuric acid, pyridinehydrochloride, hydrochloric acid, benzene sulfonic acid, p-toluenesulfonic acid, phosphoric acid, or any other known esterificationcatalyst. The amount of the catalyst in the reaction may be as little as0.01% (by weight of the reaction mixture), more often from about 0.1% toabout 5%.

The esters (A-2-b) may be obtained by the reaction of a substitutedsuccinic acid or anhydride with an epoxide or a mixture of an epoxideand water. Such reaction is similar to one involving the acid oranhydride with a glycol. For instance, the ester may be prepared by thereaction of a substituted succinic acid with one mole of ethylene oxide.Similarly, the ester may be obtained by the reaction of a substitutedsuccinic acid with two moles of ethylene oxide. Other epoxides which arecommonly available for use in such reaction include, for example,propylene oxide, styrene oxide, 1,2-butylene oxide, 2,3-butylene oxide,epichlorohydrin, cyclohexene oxide, 1,2-octylene oxide, epoxidizedsoybean oil, methyl ester of 9,10-epoxy-stearic acid, and butadienemono-epoxide. For the most part, the epoxides are the alkylene oxides inwhich the alkylene group has from 2 to about 8 carbon atoms; or theepoxidized fatty acid esters in which the fatty acid group has up toabout 30 carbon atoms and the ester group is derived from a loweralcohol having up to about 8 carbon atoms.

In lieu of the succinic acid or anhydride, a substituted succinic acidhalide may be used in the processes illustrated above for preparing theesters. Such acid halides may be acid dibromides, acid dichlorides, acidmonochlorides, and acid monobromides. The substituted succinicanhydrides and acids can be prepared by, for example, the reaction ofmaleic anhydride with a high molecular weight olefin or a halogenatedhydrocarbon such as is obtained by the chlorination of an olefin polymerdescribed previously. The reaction involves merely heating the reactantsat a temperature preferably from about 100° C. to about 250° C. Theproduct from such a reaction is an alkenyl succinic anhydride. Thealkenyl group may be hydrogenated to an alkyl group. The anhydride maybe hydrolyzed by treatment with water or steam to the correspondingacid. Another method useful for preparing the succinic acids oranhydrides involves the reaction of itaconic acid or anhydride with anolefin or a chlorinated hydrocarbon at a temperature usually within therange from about 100° C. to about 250° C. The succinic acid halides canbe prepared by the reaction of the acids or their anhydrides with ahalogenation agent such as phosphorus tribromide, phosphoruspentachloride, or thionyl chloride. These and other methods of preparingthe carboxylic esters (A-2-b) are well known in the art and need not beillustrated in further detail here. For example, see U.S. Pat. No.3,522,179 which is hereby incorporated by reference for its disclosureof the preparation of carboxylic ester compositions useful as component(A-2-b). The preparation of carboxylic ester derivative compositionsfrom acylating agents wherein the substituent groups are derived frompolyalkenes characterized by an Mn of at least about 1300 up to about5,000 and an Mw/Mn ratio of from 1.5 to about 4 is described in U.S.Pat. No. 4,234,435 which is hereby incorporated by reference. Theacylating agents described in the '435 patent are also characterized ashaving within their structure an average of at least 1.3 succinic groupsfor each equivalent weight of substituent groups.

The following examples illustrate the esters (A-2-b) and the processesfor preparing such esters.

Example E-1

A substantially hydrocarbon-substituted succinic anhydride is preparedby chlorinating a polyisobutene having a number average molecular weightof 1,000 to a chlorine content of 4.5% and then heating the chlorinatedpolyisobutene with 1.2 molar proportions of maleic anhydride at atemperature of 150°-220° C. A mixture of 874 grams (1 mole) of thesuccinic anhydride and 104 grams (1 mole) of neopentyl glycol ismaintained at 240°-250° C./30 mm for 12 hours. The residue is a mixtureof the esters resulting from the esterification of one and both hydroxygroups of the glycol.

Example E-2

The dimethyl ester of the substantially hydrocarbon-substituted succinicanhydride of Example E-1 is prepared by heating a mixture of 2185 gramsof the anhydride, 480 grams of methanol, and 1,000 cc of toluene at50°-65° C. while hydrogen chloride is bubbled through the reactionmixture for 3 hours. The mixture is then heated at 60°-65° C. for 2hours, dissolved in benzene, washed with water, dried and filtered. Thefiltrate is heated at 150° C./60 mm to remove volatile components. Theresidue is the desired dimethyl ester.

Example E-3

The substantially hydrocarbon-substituted succinic anhydride of ExampleE-1 is partially esterified with an ether-alcohol as follows. A mixtureof 550 grams (0.63 mole) of the anhydride and 190 grams (0.32 mole) of acommercial polyethylene glycol having a molecular weight of 600 isheated at 240°-250° C. for 8 hours at atmospheric pressure and 12 hoursat a pressure of 30 mm. Hg until the acid number of the reaction mixtureis reduced to about 28. The residue is the desired acidic ester.

Example E-4

A mixture of 926 grams of a polyisobutene-substituted succinic anhydridehaving an acid number of 121, 1023 grams of mineral oil, and 124 grams(2 moles per mole of the anhydride) of ethylene glycol is heated at50°-170° C. while hydrogen chloride is bubbled through the reactionmixture for 1.5 hours. The mixture is then heated to 250° C./30 mm andthe residue is purified by washing with aqueous sodium hydroxidefollowed by washing with water, then dried and filtered. The filtrate isa 50% oil solution of the desired ester.

Example E-5

A mixture of 438 grams of the polyisobutene-substituted succinicanhydride prepared as is described in Example E-1 and 333 grams of acommercial polybutylene glycol having a molecular weight of 1,000 isheated for 10 hours at 150°-160° C. The residue is the desired ester.

Example E-6

A mixture of 645 grams of the substantially hydrocarbon-substitutedsuccinic anhydride prepared as is described in Example E-1 and 44 gramsof tetramethylene glycol is heated at 100°-130° C. for 2 hours. To thismixture there is added 51 grams of acetic anhydride (esterificationcatalyst) and the resulting mixture is heated under reflux at 130°-160°C. for 2.5 hours. Thereafter the volatile components of the mixture aredistilled by heating the mixture to 196°-270° C./30 mm and then at 240°C./0.15 mm for 10 hours. The residue is the desired acidic ester.

Example E-7

A mixture of 456 grams of a polyisobutene-substituted succinic anhydrideprepared as is described in Example E-1 and 350 grams (0.35 mole) of themonophenyl ether of a polyethylene glycol having a molecular weight of1,000 is heated at 150°-155° C. for 2 hours. The product is the desiredester.

Example E-8

A dioleyl ester is prepared as follows: a mixture of 1 mole of apolyisobutene-substituted succinic anhydride prepared as in Example E-1,2 moles of a commercial oleyl alcohol, 305 grams of xylene, and 5 gramsof p-toluene sulfonic acid (esterification catalyst) is heated at150°-173° C. for 4 hours whereupon 18 grams of water is collected as thedistillate. The residue is washed with water and the organic layer driedand filtered. The filtrate is heated to 175° C./20 mm and the residue isthe desired ester.

Example E-9

An ether-alcohol is prepared by the reaction of 9 moles of ethyleneoxide with 0.9 mole of a polyisobutene-substituted phenol in which thepolyisobutene substituent has a number average molecular weight of1,000. A substantially hydrocarbon-substituted succinic acid ester ofthis ether-alcohol is prepared by heating a xylene solution of anequimolar mixture of the two reactants in the presence of a catalyticamount of p-toluene sulfonic acid at 157° C.

Example E-10

A substantiallyy hydrocarbon-substituted succinic anhydride is preparedas is described in Example E-1 except that a copolymer of 90 weightpercent of isobutene and 10 weight percent of piperylene having a numberaverage molecular weight of 66,000 is used in lieu of the polyisobutene.The anhydride has an acid number of about 22. An ester is prepared byheating a toluene solution of an equimolar mixture of the aboveanhydride and a commercial alkanol consisting substantially of C₁₂₋₁₄alcohols at the reflux temperature for 7 hours while water is removed byazeotropic distillation. The residue is heated at 150° C./3 mm to removevolatile components and diluted with mineral oil. A 50% oil solution ofthe ester is obtained.

Example E-11

(A) A mixture of 1,000 parts (0.495 mole) of polyisobutene (Mn=2020;Mw=6049) and 115 parts (1.17 moles) of maleic anhydride is heated to110° C. This mixture is heated to 184° C. in 6 hours during which 85parts (1.2 moles) of gaseous chlorine is added beneath the surface. At184°-189° C. an additional 59 parts (0.83 mole) of chlorine is addedover 4 hours. The reaction mixture is stripped by heating at 186°-190°C. with nitrogen blowing for 26 hours. The residue is the desiredpolyisobutene-substituted succinic acylating agent having asaponification equivalent number of 87 as determined by ASTM procedureD-94.

(B) A mixture of 3,225 parts (5.0 equivalents) of thepolyisobutene-substituted succinic acylating agent prepared in (A), 289parts (8.5 equivalents) of pentaerythritol and 5,204 parts of mineraloil is heated at 224°-235° C. for 5.5 hours. The reaction mixture isfiltered, at 130° C. to yield an oil solution of the desired product.

Example E-12

A mixture of about 872 grams of mineral oil and 1,000 grams of thesubstituted succinic anhydride prepared as in Example E-1 is heated toabout 150°-160° C., and 109 grams of monopentaerythritol are added whilemaintaining the reaction temperature below about 176° C. The mixturethen is heated to about 205° C. and maintained at this temperature forat least 8 hours. The mixture is blown with oxygen for an additional 8hours at about 205° C. as some water is removed. The mixture is blendedwith additional oil, if desired, and filtered. The filtrate is an oilsolution of the desired ester (45% oil).

The carboxylic esters which are described above resulting from thereaction of an acylating agent with a hydroxy-containing compound suchas an alcohol or a phenol may be further reacted with an amine(A-2-b-3), and particularly polyamines.

In one embodiment, the amount of amine (A-2-b-3) which is reacted withthe ester is an amount such that there is at least about 0.01 equivalentof the amine for each equivalent of acylating agent initially employedin the reaction with the alcohol. Where the acylating agent has beenreacted with the alcohol in an amount such that there is at least oneequivalent of alcohol for each equivalent of acylating agent, this smallamount of amine is sufficient to react with minor amounts ofnon-esterified carboxyl groups which may be present. In one preferredembodiment, the amine-modified carboxylic acid esters utilized ascomponent (A-2-b) are prepared by reacting about 1.0 to 2.0 equivalents,preferably about 1.0 to 1.8 equivalents of hydroxy compound, and up toabout 0.3 equivalent, preferably about 0.02 to about 0.25 equivalent ofpolyamine per equivalent of acylating agent.

In another embodiment, the carboxylic acid acylating agent (A-2-b-1) maybe reacted simultaneously with both the alcohol and the amine. There isgenerally at least about 0.01 equivalent of the alcohol and at least0.01 equivalent of the amine although the total amount of equivalents ofthe combination should be at least about 0.5 equivalent per equivalentof acylating agent.

The amino compound (A-2-b-3) is characterized by the presence within itsstructure of at least one HN< group and it can be a monoamine orpolyamine compound. Mixtures of two or more amino compounds can be usedin the reaction. Preferably, the amino compound contains at least oneprimary amino group (i.e., --NH₂) and more preferably the amine is apolyamine, especially a polyamine containing at least two --NH-- groups,either or both of which are primary or secondary amines. The amines maybe aliphatic, cycloaliphatic, aromatic, or heterocyclic amines.

The monoamines and polyamines must be characterized by the presencewithin their structure of at least one HN< group. Therefore, they haveat least one primary (i.e., H₂ N--) or secondary amino (i.e., HN═)group. The amines can be aliphatic, cycloaliphatic, aromatic, orheterocyclic, including aliphatic-substituted cycloaliphatic,aliphatic-substituted aromatic, aliphatic-substituted heterocyclic,cycloaliphatic-substituted aliphatic, cycloaliphatic-substitutedheterocyclic, aromatic-substituted aliphatic, aromatic-substitutedcycloaliphatic, aromatic-substituted heterocyclic,heterocyclic-substituted aliphatic, heterocyclic-substituted alicyclic,and heterocyclic-substituted aromatic amines and may be saturated orunsaturated. The amines may also contain non-hydrocarbon substituents orgroups as long as these groups do not significantly interfere with thereaction of the amines with the acylating reagents of this invention.Such non-hydrocarbon substituents or groups include lower alkoxy, loweralkyl mercapto, nitro, interrupting groups such as --O-- and --S--(e.g., as in such groups as --CH₂ --, CH₂ --X--CH₂ CH₂ -- where X is--O-- or --S--).

With the exception of the branched polyalkylene polyamine, thepolyoxyalkylene polyamines, and the high molecular weighthydrocarbyl-substituted amines described more fully hereafter, theamines ordinarily contain less than about 40 carbon atoms in total andusually not more than about 20 carbon atoms in total.

Aliphatic monoamines include mono-aliphatic and di-aliphatic substitutedamines wherein the aliphatic groups can be saturated or unsaturated andstraight or branched chain. Thus, they are primary or secondaryaliphatic amines. Such amines include, for example, mono- anddi-alkyl-substituted amines, mono- and di-alkenyl-substituted amines,and amines having one N-alkenyl substituent and one N-alkyl substituentand the like. The total number of carbon atoms in these aliphaticmonoamines will, as mentioned before, normally not exceed about 40 andusually not exceed about 20 carbon atoms. Specific examples of suchmonoamines include ethylamine, diethylamine, n-butylamine,di-n-butylamine, allylamine, isobutylamine, cocoamine, stearylamine,laurylamine, methyllaurylamine, oleylamine, N-methyl-octylamine,dodecylamine, octadecylamine, and the like.

Aromatic amines include those monoamines wherein a carbon atom of thearomatic ring structure is attached directly to the amino nitrogen. Thearomatic ring will usually be a mononuclear aromatic ring (i.e., onederived from benzene) but can include fused aromatic rings, especiallythose derived from naphthalene. Examples of aromatic monoamines includeaniline, di(paramethylphenyl) amine, naphthylamine, N-(n-butyl)aniline,and the like. Examples of aliphatic-substituted,cycloaliphatic-substituted, and heterocyclic-substituted aromaticmonoamines are para-ethoxyaniline, para-dodecylaniline,cyclohexyl-substituted naphthylamine, and thienyl-substituted aniline.

Polyamines are aliphatic, cycloaliphatic and aromatic polyaminesanalogous to the above-described monoamines except for the presencewithin their structure of additional amino nitrogens. The additionalamino nitrogens can be primary, secondary or tertiary amino nitrogens.Examples of such polyamines include N-amino-propyl-cyclohexylamines,N,N'-di-n-butyl-paraphenylene diamine, bis-(para-aminophenyl)methane,1,4-diaminocyclohexane, and the like.

Heterocycic mono- and polyamines can also be used in making thecarboxylic derivative compositions (B). As used herein, the terminology"heterocyclic mono- and polyamine(s)" is intended to describe thoseheterocyclic amines containing at least one primary or secondary aminogroup and at least one nitrogen as a heteroatom in the heterocyclicring. However, as long as there is present in the heterocyclic mono- andpolyamines at least one primary or secondary amino group, the hetero-Natom in the ring can be a tertiary amino nitrogen; that is, one thatdoes not have hydrogen attached directly to the ring nitrogen.Heterocyclic amines can be saturated or unsaturated and can containvarious substituents such as nitro, alkoxy, alkyl mercapto, alkyl,alkenyl, aryl, alkaryl, or aralkyl substituents. Generally, the totalnumber of carbon atoms in the substituents will not exceed about 20.Heterocyclic amines can contain hetero atoms other than nitrogen,especially oxygen and sulfur. Obviously they can contain more than onenitrogen hetero atom. The five- and six-membered heterocyclic rings arepreferred.

Hydroxy-substituted mono- and polyamines, analogous to the mono- andpolyamines described above are also useful in preparing carboxylicderivative (B) provided they contain at least one primary or secondaryamino group. Hydroxy-substituted amines having only tertiary aminonitrogen such as in tri-hydroxyethyl amine, are thus excluded as aminereactants but can be used as alcohols in preparing component (E) asdisclosed hereinafter. The hydroxy-substituted amines contemplated arethose having hydroxy substituents bonded directly to a carbon atom otherthan a carbonyl carbon atom; that is, they have hydroxy groups capableof functioning as alcohols. Examples of such hydroxy-substituted aminesinclude ethanolamine, di-(3-hydroxypropyl)-amine, 3-hydroxybutyl-amine,4-hydroxybutyl-amine, diethanolamine, di-(2-hydroxypropyl)-amine,N-(hydroxypropyl)-propylamine, N-(2-hydroxyethyl)-cyclohexylamine,3-hydroxycyclopentylamine, parahydroxyaniline, N-hydroxyethylpiperazine, and the like.

Hydrazine and substituted-hydrazine can also be used. At least one ofthe nitrogens in the hydrazine must contain a hydrogen directly bondedthereto. Preferably there are at least two hydrogens bonded directly tohydrazine nitrogen and, more preferably, both hydrogens are on the samenitrogen. The substituents which may be present on the hydrazine includealkyl, alkenyl, aryl, aralkyl, alkaryl, and the like. Usually, thesubstituents are alkyl, especially lower alkyl, phenyl, and substitutedphenyl such as lower alkoxy substituted phenyl or lower alkylsubstituted phenyl. Specific examples of substituted hydrazines aremethylhydrazine, N,N-dimethyl-hydrazine, N,N'-dimethylhydrazine,phenylhydrazine and N-phenyl-N'-ethylhydrazine.

The high molecular weight hydrocarbyl amines, both mono-amines andpolyamines, which can be used are generally prepared by reacting achlorinated polyolefin having a molecular weight of at least about 400with ammonia or amine. Such amines are known in the art and described,for example, in U.S. Pat. Nos. 3,275,554 and 3,438,757, both of whichare expressly incorporated herein by reference for their disclosure inregard to how to prepare these amines. All that is required for use ofthese amines is that they possess at least one primary or secondaryamino group.

Suitable amines also include polyoxyalkylene polyamines, e.g.,polyoxyalkylene diamines and polyoxyalkylene triamines, having averagemolecular weights ranging from about 200 to 4,000 and preferably fromabout 400 to 2,000.

The preferred polyoxyalkylene polyamines include the polyoxyethylene andpolyoxypropylene diamines and the polyoxypropylene triamines havingaverage molecular weights ranging from about 200 to 2,000. Thepolyoxyalkylene polyamines are commercially available and may beobtained, for example, from the Jefferson Chemical Company, Inc. underthe trade name "Jeffamines D-230, D-400, D-1000, D-2000, T-403, etc.".

U.S. Pat. Nos. 3,804,763 and 3,948,800 are expressly incorporated hereinby reference for their disclosure of such polyoxyalkylene polyamines andprocess for acylating them with carboxylic acid acylating agents whichprocesses can be applied to their reaction with the acylating reagentsused in this invention.

The most preferred amines are the alkylene polyamines, including thepolyalkylene polyamines. The alkylene polyamines include thoseconforming to the formula

    R.sup.3 (R.sup.3)N[UN(R.sup.3)].sub.n R.sup.3              (VII)

wherein n is from 1 to about 10; each R³ is independently a hydrogenatom, a hydrocarbyl group or a hydroxy-substituted or anamino-substituted hydrocarbyl group having up to about 30 atoms, withthe proviso that at least one R³ group is a hydrogen atom and U is analkylene group of about 2 to about 10 carbon atoms. Preferably U isethylene or propylene. Especially preferred are the alkylene polyamineswhere each R³ is independently hydrogen or an amino-substitutedhydrocarbyl group, with the ethylene polyamines and mixtures of ethylenepolyamines being the most preferred. Usually n will have an averagevalue of from about 2 to about 7. Such alkylene polyamines includemethylene polyamine, ethylene polyamines, butylene polyamines, propylenepolyamines, pentylene polyamines, hexylene polyamines, heptylenepolyamines, etc. The higher homologs of such amines and related aminoalkyl-substituted piperazines are also included.

The alkylene polyamines include ethylene diamine, triethylene tetramine,propylene diamine, trimethylene diamine, hexamethylene diamine,decamethylene diamine, hexamethylene diamine, decamethylene diamine,octamethylene diamine, di(heptamethylene) triamine, tripropylenetetramine, tetraethylene pentamine, trimethylene diamine, pentaethylenehexamine, di(trimethylene)triamine, N-(2-aminoethyl)piperazine,1,4-bis(2,aminoethyl)piperazine, and the like. Higher homologs as areobtained by condensing two or more of the above-illustrated alkyleneamines are useful, as are mixtures of two or more of any of theafore-described polyamines.

Ethylene polyamines, such as those mentioned above, are especiallyuseful for reasons of cost and effectiveness. Such polyamines aredescribed in detail under the heading "Diamines and Higher Amines" inThe Encyclopedia of Chemical Technology. Second Edition, Kirk andOthmer, Volume 7, pages 27-39, Interscience Publishers, Division of JohnWiley and Sons, 1965, which is hereby incorporated by reference for thedisclosure of useful polyamines. Such compounds are prepared mostconveniently by the reaction of an alkylene chloride with ammonia or byreaction of an ethylene imine with a ring-opening reagent such asammonia, etc. These reactions result in the production of the somewhatcomplex mixtures of alkylene polyamines, including cyclic condensationproducts such as piperazines. The mixtures are particularly useful inpreparing the carboxylic derivatives (B) of this invention. On the otherhand, quite satisfactory products can also be obtained by the use ofpure alkylene polyamines.

Other useful types of polyamine mixtures are those resulting fromstripping of the above-described polyamine mixtures. In this instance,lower molecular weight polyamines and volatile contaminants are removedfrom an alkylene polyamine mixture to leave as residue what is oftentermed "polyamine bottoms". In general, alkylene polyamine bottoms canbe characterized as having less than two, usually less than 1% (byweight) material boiling below about 200° C. In the instance of ethylenepolyamine bottoms, which are readily available and found to be quiteuseful, the bottoms contain less than about 2% (by weight) totaldiethylene triamine (DETA) or triethylene tetramine (TETA). A typicalsample of such ethylene polyamine bottoms obtained from the Dow ChemicalCompany of Freeport, Tex. designated "E-100" showed a specific gravityat 15.6° C. of 1.0168, a percent nitrogen by weight of 33.15 and aviscosity at 40° C. of 121 centistokes. Gas chromatography analysis ofsuch a sample showed it to contain about 0.93% "Light Ends" (mostprobably DETA), 0.72% TETA, 21.74% tetraethylene pentamine and 76.61%pentaethylene hexamine and higher (by weight). These alkylene polyaminebottoms include cyclic condensation products such as piperazine andhigher analogs of diethylene triamine, triethylene tetramine and thelike.

The carboxylic esters which are useful as component (A-2-b) are known inthe art, and the preparation of a number of these derivatives isdescribed in, for example, U.S. Pat. Nos. 3,957,854 and 4,234,435 whichare hereby incorporated by reference. The following specific examplesillustrate the preparation of the esters wherein both alcohols andamines are reacted with the acylating agent.

Example E-13

A mixture of 334 parts (0.52 equivalent) of thepolyisobutene-substituted succinic acylating agent prepared in ExampleE-2, 548 parts of mineral oil, 30 parts (0.88 equivalent) ofpentaerythritol and 8.6 parts (0.0057 equivalent) of Polyglycol 112-2demulsifier from Dow Chemical Company is heated at 150° C. for 2.5hours. The reaction mixture is heated to 210° C. in 5 hours and held at210° C. for 3.2 hours. The reaction mixture is cooled to 190° C. and 8.5parts (0.2 equivalent) of a commercial mixture of ethylene polyamineshaving an average of about 3 to about 10 nitrogen atoms per molecule areadded. The reaction mixture is stripped by heating at 205° C. withnitrogen blowing for 3 hours, then filtered to yield the filtrate as anoil solution of the desired product.

Example E-14

A mixture is prepared by the addition of 14 parts of aminopropyldiethanolamine to 867 parts of the oil solution of the product preparedin Example E-11 at 190°-200° C. The reaction mixture is held at 195° C.for 2.25 hours, then cooled to 120° C. and filtered. The filtrate is anoil solution of the desired product.

Example E-15

A mixture is prepared by the addition of 7.5 parts of piperazine to 867parts of the oil solution of the product prepared in Example E-11 at190° C. The reaction mixture is heated at 190°-205° C. for 2 hours, thencooled to 130° C. and filtered. The filtrate is an oil solution of thedesired product.

Example E-16

A mixture of 322 parts (0.5 equivalent) of the polyisobutene-substitutedsuccinic acylating agent prepared in Example E-2, 68 parts (2.0equivalents) of pentaerythritol and 508 parts of mineral oil is heatedat 204°-227° C. for 5 hours. The reaction mixture is cooled to 162° C.and 5.3 parts (0.13 equivalent) of a commercial ethylene polyaminemixture having an average of about 3 to 10 nitrogen atoms per moleculeis added. The reaction mixture is heated at 162°-163° C. for one hour,then cooled to 130° C. and filtered. The filtrate is an oil solution ofthe desired product.

Example E-17

The procedure for Example E-16 is repeated except the 5.3 parts (0.13equivalent) of ethylene polyamine is replaced by 21 parts (0.175equivalent) of tris(hydroxymethyl)aminomethane.

Example E-18

A mixture of 1,480 parts of the polyisobutene-substituted succinicacylating agent prepared in Example E-6, 115 parts (0.53 equivalent) ofa commercial mixture of C₁₂₋₁₈ straight-chain primary alcohols, 87 parts(0.594 equivalent) of a commercial mixture of C₈₋₁₀ straight-chainprimary alcohols, 1,098 parts of mineral oil and 400 parts of toluene isheated to 120° C. At 120° C., 1.5 parts of sulfuric acid are added andthe reaction mixture is heated to 160° C. and held for 3 hours. To thereaction mixture are then added 158 parts (2.0 equivalents) of n-butanoland 1.5 parts of sulfuric acid. The reaction mixture is heated at 160°C. for 15 hours, and 12.6 parts (0.088 equivalent) of aminopropylmorpholine are added. The reaction mixture is held at 160° C. for anadditional 6 hours, stripped at 150° C. under vacuum and filtered toyield an oil solution of the desired product.

Example E-19

(A) A mixture of 1,000 parts of polyisobutene having a number averagemolecular weight of about 1,000 and 108, parts (1.1 moles) of maleicanhydride is heated to about 190° C. and 100 parts (1.43 moles) ofchlorine are added beneath the surface over a period of about 4 hourswhile maintaining the temperature at about 185°-190° C. The mixture thenis blown with nitrogen at this temperature for several hours, and theresidue is the desired polyisobutene-substituted succinic acylatingagent.

(B) A solution of 1,000 parts of the above-prepared acylating agent in857 parts of mineral oil is heated to about 150° C. with stirring, and109 parts (3.2 equivalents) of pentaerythritol are added with stirring.The mixture is blown with nitrogen and heated to about 200° C. over aperiod of about 14 hours to form an oil solution of the desiredcarboxylic ester intermediate. To the intermediate, there are added19.25 parts (0.46 equivalent) of a commercial mixture of ethylenepolyamines having an average of about 3 to about 10 nitrogen atoms permolecule. The reaction mixture is stripped by heating at 205° C. withnitrogen blowing for 3 hours and filtered. The filtrate is an oilsolution (45% oil) of the desired amine-modified carboxylic ester whichcontains 0.35% nitrogen.

Example E-20

(A) A mixture of 1,000 parts (0.495 mole) of polyisobutene having anumber average molecular weight of 2,020 and a weight average molecularweight of 6,049 and 115 parts (1.17 moles) of maleic anhydride is heatedto 184° C. over 6 hours, during which time 85 parts (1.2 moles) ofchlorine are added beneath the surface. An additional 59 parts (0.83mole) of chlorine are added over 4 hours at 184°-189° C. The mixture isblown with nitrogen at 186°-190° C. for 26 hours. The residue is apolyisobutene-substituted succinic anhydride having a total acid numberof 95.3.

(B) A solution of 409 parts (0.66 equivalent) of the substitutedsuccinic anhydride in 191 parts of mineral oil is heated to 150° C. and42.5 parts (1.19 equivalent) of pentaerythritol are added over 10minutes, with stirring, at 145°-150° C. The mixture is blown withnitrogen and heated to 205°-210° C. over about 14 hours to yield an oilsolution of the desired polyester intermediate.

Diethylene triamine, 4.74 parts (0.138 equivalent), is added overone-half hour at 160° C. with stirring, to 988 parts of the polyesterintermediate (containing 0.69 equivalent of substituted succinicacylating agent and 1.24 equivalents of pentaerythritol). Stirring iscontinued at 160° C. for one hour, after which 289 parts of mineral oilare added. The mixture is heated for 16 hours at 135° C. and filtered atthe same temperature, using a filter aid material. The filtrate is a 35%solution in mineral oil of the desired amine-modified polyester. It hasa nitrogen content of 0.16% and a residual acid number of 2.0.

Example E-21

Following the procedure of Example E-20, 988 parts of the polyesterintermediate of that example are reacted with 5 parts (0.138 equivalent)of triethylene tetramine. The product is diluted with 290 parts ofmineral oil to yield a 35% solution of the desired amine-modifiedpolyester. It contains 0.15% nitrogen and has a residual acid number of2.7.

Example E-22

Pentaerythritol, 42.5 parts (1.19 equivalents) is added over 5 minutesat 150° C. to a solution in 208 parts of mineral oil of 448 parts (0.7equivalent) of a polyisobutene-substituted succinic anhydride similar tothat of Example E-20 but having a total acid number of 92. The mixtureis heated to 205° C. over 10 hours and blown with nitrogen for 6 hoursat 205°-210° C. It is then diluted with 384 parts of mineral oil andcooled to 165° C., and 5.89 parts (0.14 equivalent) of a commercialethylene polyamine mixture containing an average of 3-7 nitrogen atomsper molecule are added over 30 minutes at 155°-160° C. Nitrogen blowingis continued for one hour, after which the mixture is diluted with anadditional 304 parts of oil. Mixing is continued at 130°-135° C. for 15hours after which the mixture is cooled and filtered using a filter aidmaterial. The filtrate is a 35% solution in mineral oil of the desiredamine-modified polyester. It contains 0.147% nitrogen and has a residualacid number of 2.07.

Example E-23

A solution of 417 parts (0.7 equivalent) of thepolyisobutene-substituted succinic anhydride of Example E-20 in 194parts of mineral oil is heated to 153° C. and 42.8 parts (1.26equivalents) of pentaerythritol are added. The mixture is heated at153°-228° C. for about 6 hours. It is then cooled to 170° C. and dilutedwith 375 parts of mineral oil. It is further cooled to 156°-158° C. and5.9 parts (0.14 equivalent) of the ethylene polyamine mixture of ExampleE-22 are added over one-half hour. The mixture is stirred at 158°-160°C. for one hour and diluted with an additional 295 parts of mineral oil.It is blown with nitrogen at 135° C. for 16 hours and filtered at 135°C. using a filter aid material. The filtrate is the desired 35% solutionin mineral oil of the amine-modified polyester. It contains 0.16%nitrogen and has a total acid number of 2.0. (A-2-c) The Neutral andBasic Alkali Metal and Alkaline Earth Metal Salts.

The oil solutions used in the present invention also may contain, andpreferably do contain, at least one neutral or basic alkali metal oralkaline earth metal salt of at least one acidic organic compound. Suchsalt compounds generally are referred to as ash-containing detergents.The acidic organic compound may be at least one sulfur acid, carboxylicacid, phosphorus acid, or phenol, or mixtures thereof.

The alkali metals include lithium, sodium and potassium, with sodium andpotassium being preferred. Calcium, magnesium, barium and strontium arethe preferred alkaline earth metals. Salts containing a mixture of ionsof two or more of these alkaline earth metals can be used.

The salts which are useful as component (A-2-c) can be neutral or basic.The neutral salts contain an amount of metal which is just sufficient toneutralize the acidic groups present in the salt anion, and the basicsalts contain an excess of the metal cation. Generally, the basic oroverbased salts are preferred. The basic or overbased salts will havemetal ratios of up to about 40 and more particularly from about 2 toabout 30 or 40.

A commonly employed method for preparing the basic (or overbased) saltscomprises heating a mineral oil solution of the acid with astoichiometric excess of a metal neutralizing agent, e.g., a metaloxide, hydroxide, carbonate, bicarbonate, sulfide, etc., at temperaturesabove about 50° C. In addition, various promoters may be used in theneutralizing process to aid in the incorporation of the large excess ofmetal. These promoters include such compounds as the phenolicsubstances, e.g., phenol, naphthol, alkylphenol, thiophenol, sulfurizedalkylphenol and the various condensation products of formaldehyde with aphenolic substance; alcohols such as methanol, 2-propanol, octylalcohol, cellosolve carbitol, ethylene, glycol, stearyl alcohol, andcyclohexyl alcohol; amines such as aniline, phenylenediamine,phenothiazine, phenyl-beta-naphthylamine, and dodecyl amine, etc. Aparticularly effective process for preparing the basic alkaline earthmetal salts comprises mixing the acid with an excess of the basicalkaline earth metal in the presence of the phenolic promoter and asmall amount of water and carbonating the mixture at an elevatedtemperature, e.g., 60° C. to about 200° C.

A general description of some of the basic alkali metal salts iscontained in U.S. Pat. No. 4,326,972 (Chamberlin). This patent is herebyincorporated by reference for its disclosure of useful alkali metalsalts and methods of preparing said salts.

As mentioned above, the acidic organic compound from which the salt(A-2-c) is derived may be at least one sulfur acid, carboxylic acid,phosphorus acid, or phenol or mixtures thereof. The sulfur acids includethe sulfonic acids, thiosulfonic, sulfinic, sulfenic, partial estersulfuric, sulfurous and thiosulfuric acids.

The sulfonic acids which are useful in preparing component (A-2-c)include those represented by the formulae

    R.sub.x T(SO.sub.3 H).sub.y                                (VIII)

and

    R'(SO.sub.3 H).sub.r                                       (IX)

In these formulae, R' is an aliphatic or aliphatic-substitutedcycloaliphatic hydrocarbon or essentially hydrocarbon group free fromacetylenic unsaturation and containing up to about 60 carbon atoms. WhenR' is aliphatic, it usually contains at least about 15 carbon atoms;when it is an aliphatic-substituted cycloaliphatic group, the aliphaticsubstituents usually contain a total of at least about 12 carbon atoms.Examples of R' are alkyl, alkenyl and alkoxyalkyl radicals, andaliphatic-substituted cycloaliphatic groups wherein the aliphaticsubstituents are alkyl, alkenyl, alkoxy, alkoxyalkyl, carboxyalkyl andthe like. Generally, the cycloaliphatic nucleus is derived from acycloalkane or a cycloalkene such as cyclopentane, cyclohexane,cyclohexene or cyclopentene. Specific examples of R' arecetylcyclohexyl, laurylcyclohexyl, cetyloxyethyl, octadecenyl, andgroups derived from petroleum, saturated and unsaturated paraffin wax,and olefin polymers including polymerized monoolefins and diolefinscontaining about 2-8 carbon atoms per olefinic monomer unit. R' can alsocontain other substituents such as phenyl, cycloalkyl, hydroxy,mercapto, halo, nitro, amino, nitroso, lower alkoxy, loweralkylmercapto, carboxy, carbalkoxy, oxo or thio, or interrupting groupssuch as --NH--, --O-- or --S--, as long as the essentially hydrocarboncharacter thereof is not destroyed.

R in Formula VIII is generally a hydrocarbon or essentially hydrocarbongroup free from acetylenic unsaturation and containing from about 4 toabout 60 aliphatic carbon atoms, preferably an aliphatic hydrocarbongroup such as alkyl or alkenyl. It may also, however, containsubstituents or interrupting groups such as those enumerated aboveprovided the essentially hydrocarbon character thereof is retained. Ingeneral, any non-carbon atoms present in R' or R do not account for morethan 10% of the total weight thereof.

T is a cyclic nucleus which may be derived from an aromatic hydrocarbonsuch as benzene, naphthalene, anthracene or biphenyl, or from aheterocyclic compound such as pyridine, indole or isoindole. Ordinarily,T is an aromatic hydrocarbon nucleus, especially a benzene ornaphthalene nucleus.

The subscript x is at least 1 and is generally 1-3. The subscripts r andy have an average value of about 1-2 per molecule and are generally also1.

The sulfonic acids are generally petroleum sulfonic acids orsynthetically prepared alkaryl sulfonic acids. Among the petroleumsulfonic acids, the most useful products are those prepared by thesulfonation of suitable petroleum fractions with a subsequent removal ofacid sludge, and purification. Synthetic alkaryl sulfonic acids areprepared usually from alkylated benzenes such as the Friedel-Craftsreaction products of benzene and polymers such as tetrapropylene. Thefollowing are specific examples of sulfonic acids useful in preparingthe salts (A-2-c). It is to be understood that such examples serve alsoto illustrate the salts of such sulfonic acids useful as component(A-2-c). In other words, for every sulfonic acid enumerated, it isintended that the corresponding neutral and basic alkali metal andalkaline earth metal salts thereof are also understood to beillustrated. (The same applies to the lists of carboxylic acidphosphonic acid and phenol materials listed below.) Such sulfonic acidsinclude mahogany sulfonic acids, bright stock sulfonic acids, petrolatumsulfonic acids, mono- and polywax-substituted naphthalene sulfonicacids, cetylchlorobenzene sulfonic acids, cetylphenol sulfonic acids,cetylphenol disulfide sulfonic acids, cetoxycapryl benzene sulfonicacids, dicetyl thianthrene sulfonic acids, dilauryl beta-naphtholsulfonic acids, dicapryl nitronaphthalene sulfonic acids, saturatedparaffin wax sulfonic acids, unsaturated paraffin wax sulfonic acids,hydroxy-substituted paraffin wax sulfonic acids, tetraisobutylenesulfonic acids, tetra-amylene sulfonic acids, chloro-substitutedparaffin wax sulfonic acids, nitroso-substituted paraffin wax sulfonicacids, petroleum naphthene sulfonic acids, cetylcyclopentyl sulfonicacids, lauryl cyclohexyl sulfonic acids, mono- and polywax-substitutedcyclohexyl sulfonic acids, dodecylbenzene sulfonic acids, "dimeralkylate" sulfonic acids, and the like.

Alkyl-substituted benzene sulfonic acids wherein the alkyl groupcontains at least 8 carbon atoms including dodecyl benzene "bottoms"sulfonic acids are particularly useful. The latter are acids derivedfrom benzene which has been alkylated with propylene tetramers orisobutene trimers to introduce 1, 2, 3, or more branched-chain C₁₂substituents on the benzene ring. Dodecyl benzene bottoms, principallymixtures of mono- and di-dodecyl benzenes, are available as by-productsfrom the manufacture of household detergents. Similar products obtainedfrom alkylation bottoms formed during manufacture of linear alkylsulfonates (LAS) are also useful in making the sulfonates used in thisinvention.

The production of sulfonates from detergent manufacture by-products byreaction with, e.g., SO₃, is well known to those skilled in the art.See, for example, the article "Sulfonates" in Kirk-Othmer, Encyclopediaof Chemical Technology, Second Edition, Vol. 19, pp. 291 et seq.published by John Wiley & Sons, N.Y. (1969).

Other descriptions of basic sulfonate salts which can be incorporatedinto the oil solutions of this invention as component (A-2-c), andtechniques for making them can be found in the following U.S. Pat. Nos.:2,174,110; 2,202,781; 2,239,974; 2,319,121; 2,337,552; 3,488,284;3,595,790; and 3,798,012. These are hereby incorporated by reference fortheir disclosures in this regard.

Suitable carboxylic acids from which useful metal salts can be preparedinclude aliphatic, cycloaliphatic and aromatic mono- and polybasiccarboxylic acids free from acetylenic unsaturation, including naphthenicacids, alkyl- or alkenyl-substituted cyclopentanoic acids, alkyl- oralkenyl-substituted cyclohexanoic acids, and alkyl- oralkenyl-substituted aromatic carboxylic acids. The aliphatic acidsgenerally contain from about 8 to about 50, and preferably from about 12to about 25 carbon atoms. The cycloaliphatic and aliphatic carboxylicacids are preferred, and they can be saturated or unsaturated. Specificexamples include 2-ethylhexanoic acid, linolenic acid, propylenetetramer-substituted maleic acid, behenic acid, isostearic acid,pelargonic acid, capric acid, palmitoleic acid, linoleic acid, lauricacid, oleic acid, ricinoleic acid, undecyclic acid,dioctylcyclopentanecarboxylic acid, myristic acid,dilauryldecahydronaphthalene-carboxylic acid,stearyl-octahydroindenecarboxylic acid, palmitic acid, alkyl- andalkenylsuccinic acids, acids formed by oxidation of petrolatum or ofhydrocarbon waxes, and commercially available mixtures of two or morecarboxylic acids such as tall oil acids, rosin acids, and the like.

The equivalent weight of the acidic organic compound is its molecularweight divided by the number of acidic groups (i.e., sulfonic acid orcarboxy groups) present per molecule.

The pentavalent phosphorus acids useful in the preparation of the salts(A-2-c) may be represented by the formula ##STR7## wherein each of R³and R⁴ is hydrogen or a hydrocarbon or essentially hydrocarbon grouppreferably having from about 4 to about 25 carbon atoms, at least one ofR³ and R⁴ being hydrocarbon or essentially hydrocarbon; each of X¹, X²,X³ and X⁴ is oxygen or sulfur; and each of a and b is 0 or 1. Thus, itwill be appreciated that the phosphorus acid may be an organophosphoric,phosphonic or phosphinic acid, or a thio analog of any of these.

The phosphorus acids may be those of the formula ##STR8## wherein R³ isa phenyl group or (preferably) an alkyl group having up to 18 carbonatoms, and R⁴ is hydrogen or a similar phenyl or alkyl group. Mixturesof such phosphorus acids are often preferred because of their ease ofpreparation.

Salt (A-2-c) may also be prepared from phenols; that is, compoundscontaining a hydroxy group bound directly to an aromatic ring. The term"phenol" as used herein includes compounds having more than one hydroxygroup bound to an aromatic ring, such as catechol, resorcinol andhydroquinone. It also includes alkylphenols such as the cresols andethylphenols, and alkenylphenols. Preferred are phenols containing atleast one alkyl substituent containing about 3-100 and especially about6-50 carbon atoms, such as heptylphenol, octylphenol, dodecylphenol,tetrapropene-alkylated phenol, octadecylphenol and polybutenylphenols.Phenols containing more than one alkyl substituent may also be used, butthe monoalkylphenols are preferred because of their availability andease of production.

Also useful are condensation products of the above-described phenolswith at least one lower aldehyde or ketone, the term "lower" denotingaldehydes and ketones containing not more than 7 carbon atoms. Suitablealdehydes include formaldehyde, acetaldehyde, propionaldehyde, thebutyraldehydes, the valeraldehydes and benzaldehyde. Also suitable arealdehyde-yielding reagents such as paraformaldehyde, trioxane, methylol,Methyl Formcel and paraldehyde. Formaldehyde and theformaldehyde-yielding reagents are especially preferred.

In one preferred embodiment, the metal salts (A-2-c) are basic metalsalts having metal ratios of at least about, 2 and more generally fromabout 4 to about 40, preferably from about 6 to about 30 and especiallyfrom about 8 to about 25.

In another embodiment, the alkali metal salts (A-2-c) are basic saltswhich are oil-soluble dispersions prepared by contacting for a period oftime sufficient to form a stable dispersion, at a temperature betweenthe solidification temperature of the reaction mixture and itsdecomposition temperature:

(C-1) at least one acidic gaseous material selected from the groupconsisting of carbon dioxide, hydrogen sulfide and sulfur dioxide, with

(C-2) a reaction mixture comprising

(C-2-a) at least one oil-soluble sulfonic acid, or derivative thereofsusceptible to overbasing;

(C-2-b) at least one alkali metal or basic alkali metal compound;

(C-2-c) at least one lower aliphatic alcohol, alkyl phenol, orsulfurized alkyl phenol; and

(C-2-d) at least one oil-soluble carboxylic acid or functionalderivative thereof.

When (C-2-c) is an alkyl phenol or a sulfurized alkyl phenol, component(C-2-d) is optional. A satisfactory basic sulfonic acid salt can beprepared with or without the carboxylic acid in the mixture (C-2).

Reagent (C-1) is at least one acidic gaseous material which may becarbon dioxide, hydrogen sulfide or sulfur dioxide; mixtures of thesegases are also useful. Carbon dioxide is preferred.

As mentioned above, component (C-2) generally is a mixture containing atleast four components of which component (C-2-a) is at least oneoil-soluble sulfonic acid as previously defined, or a derivative thereofsusceptible to overbasing. Mixtures of sulfonic acids and/or theirderivatives may also be used. Sulfonic acid derivatives susceptible tooverbasing include their metal salts, especially the alkaline earth,zinc and lead salts; ammonium salts and amine salts (e.g., theethylamine, butylamine and ethylene polyamine salts); and esters such asthe ethyl, butyl and glycerol esters.

Component (C-2-b) is at least one alkali metal or a basic compoundthereof. Illustrative of basic alkali metal compounds are thehydroxides, alkoxides (typically those in which the alkoxy groupcontains up to 10 and preferably up to 7 carbon atoms), hydrides andamides. Thus, useful basic alkali metal compounds include sodiumhydroxide, potassium hydroxide, lithium hydroxide, sodium propoxide,lithium methoxide, potassium ethoxide, sodium butoxide, lithium hydride,sodium hydride, potassium hydride, lithium amide, sodium amide andpotassium amide. Especially preferred are sodium hydroxide and thesodium lower alkoxides (i.e., those containing up to 7 carbon atoms).The equivalent weight of component (C-2-b) for the purpose of thisinvention is equal to its molecular weight, since the alkali metals aremonovalent.

Component (C-2-c) may be at least one lower aliphatic alcohol,preferably a monohydric or dihydric alcohol. Illustrative alcohols aremethanol, ethanol, 1-propanol, 1-hexanol, isopropanol, isobutanol,2-pentanol, 2,2-dimethyl-1-propanol, ethylene glycol, 1-3-propanedioland 1,5-pentanediol. The alcohol also may be a glycol ether such asMethyl Cellosolve. Of these, the preferred alcohols are methanol,ethanol and propanol, with methanol being especially preferred.

Component (C-2-c) also may be at least one alkyl phenol or sulfurizedalkyl phenol. The sulfurized alkyl phenols are preferred, especiallywhen (C-2-b) is potassium or one of its basic compounds such aspotassium hydroxide. As used herein, the term "phenol" includescompounds having more than one hydroxy group bound to an aromatic ring,and the aromatic ring may be a benzyl or naphthyl ring. The term "alkylphenol" includes mono- and di-alkylated phenols in which each alkylsubstituent contains from about 6 to about 100 carbon atoms, preferablyabout 6 to about 50 carbon atoms.

Illustrative alkyl phenols include heptylphenols, octylphenols,decylphenols, dodecylphenols, polypropylene (Mn of about150)-substituted phenols, polyisobutene (Mn of about 1200)-substitutedphenols, cyclohexyl phenols.

Also useful are condensation products of the above-described phenolswith at least one lower aldehyde or ketone, the term "lower" denotingaldehydes and ketones containing not more than 7 carbon atoms. Suitablealdehydes include formaldehyde, acetaldehyde, propionaldehyde, thebutyraldehydes, the valeraldehydes and benzaldehyde. Also suitable arealdehyde-yielding reagents such as paraformaldehyde, trioxane, methylol,Methyl Formcel and paraldehyde. Formaldehyde and theformaldehyde-yielding reagents are especially preferred.

The sulfurized alkylphenols include phenol sulfides, disulfides orpolysulfides. The sulfurized phenols can be derived from any suitablealkylphenol by technique known to those skilled in the art, and manysulfurized phenols are commercially available. The sulfurizedalkylphenols may be prepared by reacting an alkylphenol with elementalsulfur and/or a sulfur monohalide (e.g., sulfur monochloride). Thisreaction may be conducted in the presence of excess base to result inthe salts of the mixture of sulfides, disulfides or polysulfides thatmay be produced depending upon the reaction conditions. It is theresulting product of this reaction which is used in the preparation ofcomponent (C-2). U.S. Pat. Nos. 2,971,940 and 4,309,293 disclose varioussulfurized phenols which are illustrative of component (C-2-c), and suchdisclosures of these patents are hereby incorporated by reference.

The following non-limiting examples illustrate the preparation ofalkylphenols and sulfurized alkylphenols useful as component (C-2-c).

Example 1-C

While maintaining a temperature of 55° C., 100 parts phenol and 68 partssulfonated polystyrene catalyst (marketed as Amberlyst-15 by Rohm andHaas Company) are charged to a reactor equipped with a stirrer,condenser, thermometer and subsurface gas inlet tube. The reactorcontents are then heated to 120° C. while nitrogen blowing for 2 hours.Propylene tetramer (1232 parts) is charged, and the reaction mixture isstirred at 120° C. for 4 hours. Agitation is stopped, and the batch isallowed to settle for 0.5 hour. The crude supernatant reaction mixtureis filtered and vacuum stripped until a maximum of 0.5% residualpropylene tetramer remains.

Example 2-C

Benzene (217 parts) is added to phenol (324 parts, 3.45 moles) at 38° C.and the mixture is heated to 47° C. Boron trifluoride (8.8 parts, 0.13mole) is blown into, the mixture over a one-half hour period at 38°-52°C. Polyisobutene (1000 parts, 1.0 mole) derived from the polymerizationof C₄ monomers predominating in isobutylene is added to the mixture at52°-58° C. over a 3.5 hour period. The mixture is held at 52° C. for 1additional hour. A 26% solution of aqueous ammonia (15 parts) is addedand the mixture is heated to 70° C. over a 2-hour period. The mixture isthen filtered and the filtrate is the desired crudepolyisobutene-substituted phenol. This intermediate is stripped byheating 1465 parts to 167° C. and the pressure is reduced to 10 mm. asthe material is heated to 218° C. in a 6-hour period. A 64% yield ofstripped polyisobutene-substituted phenol (Mn=885) is obtained as theresidue.

Example 3-C

A reactor equipped with a stirrer, condenser, thermometer and subsurfaceaddition tube is charged with 1000 parts of the reaction product ofExample 1-C. The temperature is adjusted to 48°-49° C. and 319 partssulfur dichloride is added while the temperature is kept below 60° C.The batch is then heated to 88°-93° C. while nitrogen blowing until theacid number (using bromphenol blue indicator) is less than 4.0. Diluentoil (400 parts) is then added, and the mixture is mixed thoroughly.

Example 4-C

Following the procedure of Example 3-C, 1000 parts of the reactionproduct of Example 1-C is reacted with 175 parts of sulfur dichloride.The reaction product is diluted with 400 parts diluent oil.

Example 5-C

Following the procedure of Example 3-C, 1000 parts of the reactionproduct of Example 1-C is reacted with 319 parts of sulfur dichloride.Diluent oil (788 parts) is added to the reaction product, and thematerials are mixed thoroughly.

Example 6-C

Following the procedure of Example 4-C, 1000 parts of the reactionproduct of Example 2-C are reacted with 44 parts of sulfur dichloride toproduce the sulfurized phenol.

Example 7-C

Following the procedure of Example 5-C, 1000 parts of the reactionproduct of Example 2-C are reacted with 80 parts of sulfur dichloride.

The equivalent weight of component (C-2-c) is its molecular weightdivided by the number of hydroxy groups per molecule.

Component (C-2-d) is at least one oil-soluble carboxylic acid aspreviously described, or functional derivative thereof. Especiallysuitable carboxylic acids are those of the formula R⁵ (COOH)_(n),wherein n is an integer from 1 to 6 and is preferably 1 or 2 and R⁵ is asaturated or substantially saturated aliphatic radical (preferably ahydrocarbon radical) having at least 8 aliphatic carbon atoms. Dependingupon the value of n, R⁵ will be a monovalent to hexavalent radical.

R⁵ may contain non-hydrocarbon substituents provided they do not altersubstantially its hydrocarbon character. Such substituents arepreferably present in amounts of not more than about 20% by weight.Exemplary substituents include the non-hydrocarbon substituentsenumerated hereinabove with reference to component (C-2-a). R⁵ may alsocontain olefinic unsaturation up to a maximum of about 5% and preferablynot more than 2% olefinic linkages based upon the total number ofcarbon-to-carbon covalent linkages present. The number of carbon atomsin R⁵ is usually about 8-700 depending upon the source, of R⁵. Asdiscussed below, a preferred series of carboxylic acids and derivativesis prepared by reacting an olefin polymer or halogenated olefin polymerwith an alpha,beta-unsaturated acid or its anhydride such as acrylic,methacrylic, maleic or fumaric acid or maleic anhydride to form thecorresponding substituted acid or derivative thereof. The R⁵ groups inthese products have a number average molecular weight from about 150 toabout 10,000 and usually from about 700 to about 5000, as determined,for example, by gel permeation chromatography.

The monocarboxylic acids useful as component (C-2-d) have the formula R⁵COOH. Examples of such acids are caprylic, capric, palmitic, stearic,isostearic, linoleic and behenic acids. A particularly preferred groupof monocarboxylic acids is prepared by the reaction of a halogenatedolefin polymer, such as a chlorinated polybutene, with acrylic acid ormethacrylic acid.

Suitable dicarboxylic acids include the substituted succinic acidshaving the formula ##STR9## wherein R⁶ is the same as R⁵ as definedabove. R⁶ may be an olefin polymer-derived group formed bypolymerization of such monomers as ethylene, propylene, 1-butene,isobutene, 1-pentene, 2-pentene, 1-hexene and 3-hexene. R⁶ may also bederived from a high molecular weight substantially saturated petroleumfraction. The hydrocarbon-substituted succinic acids and theirderivatives constitute the most preferred class of carboxylic acids foruse as component (C-2-d).

The above-described classes of carboxylic acids derived from olefinpolymers, and their derivatives, are well known in the art, and methodsfor their preparation as well as representative examples of the typesuseful in the present invention are described in detail in a number ofU.S. Patents.

Functional derivatives of the above-discussed acids useful as component(C-2-d) include the anhydrides, esters, amides, imides, amidines andmetal or ammonium salts. The reaction products of olefinpolymer-substituted succinic acids and mono- or polyamines, particularlypolyalkylene polyamines, having up to about 10 amino nitrogens areespecially suitable. These reaction products generally comprise mixturesof one or more of amides, imides and amidines. The reaction products ofpolyethylene amines containing up to about 10 nitrogen atoms andpolybutene-substituted succinic anhydride wherein the polybutene radicalcomprises principally isobutene units are particularly useful. Includedin this group of functional derivatives are the compositions prepared bypost-treating the amine-anhydride reaction product with carbondisulfide, boron compounds, nitriles, urea, thiourea, guanidine,alkylene oxides or the like. The half-amide, half-metal salt andhalf-ester, half-metal salt derivatives of such substituted succinicacids are also useful.

Also useful are the esters prepared by the reaction of the substitutedacids or anhydrides with a mono- or polyhydroxy compound, such as analiphatic alcohol or a phenol. Preferred are the esters of olefinpolymer-substituted succinic acids or anhydrides and polyhydricaliphatic alcohols containing 2-10 hydroxy groups and up to about 40aliphatic carbon atoms. This class of alcohols includes ethylene glycol,glycerol, sorbitol, pentaerythritol, polyethylene glycol,diethanolamine, triethanolamine, N,N'-di(hydroxyethyl)ethylene diamineand the like. When the alcohol contains reactive amino groups, thereaction product may comprise products resulting from the reaction ofthe acid group with both the hydroxy and amino functions. Thus, thisreaction mixture can include half-esters, half-amides, esters, amides,and imides.

The ratios of equivalents of the constituents of reagent (C-2) may varywidely. In general, the ratio of component (C-2-b) to (C-2-a) is atleast about 4:1 and usually not more than about 40:1, preferably between6:1 and 30:1 and most preferably between 8:1 and 25:1. While this ratiomay sometimes exceed 40:1, such an excess normally will serve no usefulpurpose.

The ratio of equivalents of component (C-2-c) to component (C-2-a) isbetween about 1:20 and 80:1, and preferably between about 2:1 and 50:1.As mentioned above, when component (C-2-c) is an alkyl phenol orsulfurized alkyl phenol, the inclusion of the carboxylic acid (C-2-d) isoptional. When present in the mixture, the ratio of equivalents ofcomponent (C-2-d) to component (C-2-a) generally is from about 1:1 toabout 1:20 and preferably from about 1:2 to about 1:10.

Up to about a stoichiometric amount of acidic material (C-1) is reactedwith (C-2). In one embodiment, the acidic material is metered into the(C-2) mixture and the reaction is rapid. The rate of addition of (C-1)is not critical, but may have to be reduced if the temperature of themixture rises too rapidly due to the exothermicity of the reaction.

When (C-2-c) is an alcohol, the reaction temperature is not critical.Generally, it will be between the solidification temperature of thereaction mixture and its decomposition temperature (i.e., the lowestdecomposition temperature of any component thereof). Usually, thetemperature will be from about 25° C. to about 200° C. and preferablyfrom about 50° C. to about 150° C. Reagents (C-1) and (C-2) areconveniently contacted at the reflux temperature of the mixture. Thistemperature will obviously depend upon the boiling points of the variouscomponents; thus, when methanol is used as component (C-2-c), thecontact temperature will be at or below the reflux temperature ofmethanol.

When reagent (C-2-c) is an alkyl phenol or a sulfurized alkyl phenol,the temperature of the reaction must be at or above the water-diluentazeotrope temperature so that the water formed in the reaction can beremoved.

The reaction is ordinarily conducted at atmospheric pressure, althoughsuperatmospheric pressure often expedites the reaction and promotesoptimum utilization of reagent (C-1). The process can also be carriedout at reduced pressure but, for obvious practical reasons, this israrely done.

The reaction is usually conducted in the presence of a substantiallyinert, normally liquid organic diluent such as a low viscositylubricating oil, which functions as both the dispersing and reactionmedium. This diluent will comprise at least about 10% of the totalweight of the reaction mixture. Ordinarily it will not exceed about 80%by weight, and it is preferably about 30-70% thereof.

Upon completion of the reaction, any solids in the mixture arepreferably removed by filtration or other conventional means.Optionally, readily removable diluents, the alcoholic promoters, andwater formed during the reaction can be removed by conventionaltechniques such as distillation. It is usually desirable to removesubstantially all water from the reaction mixture since the presence ofwater may lead to difficulties in filtration and to the formation ofundesirable emulsions in fuels and lubricants. Any such water present isreadily removed by heating at atmospheric or reduced pressure or byazeotropic distillation. In one preferred embodiment, when basicpotassium sulfonates are desired as component (A-2-c), the potassiumsalt is prepared using carbon dioxide and the sulfurized alkylphenols ascomponent (C-2-c). The use of the sulfurized phenols results in basicsalts of higher metal ratios and the formation of more uniform andstable salts.

The chemical structure of the alkali metal salts (A-2-c) is not knownwith certainty. The basic salts or complexes may be solutions or, morelikely, stable dispersions. Alternatively, they may be regarded as"polymeric salts" formed by the reaction of the acidic material, theoil-soluble acid being overbased, and the metal compound. In view of theabove, these compositions are most conveniently defined by reference tothe method by which they are formed.

The above-described procedures for preparing alkali metal salts ofsulfonic acids having a metal ratio of at least about 2 and preferably ametal ratio between about 4 to 40 using alcohols as component (C-2-c) isdescribed in more detail in U.S. Pat. No. 4,326,972 which has beenincorporated by reference for the disclosures of such processes.

The preparation of oil-soluble dispersions of alkali metal sulfonatesuseful as component (A-2-c) in the oil compositions of this invention isillustrated in the following examples.

Example S-1

To a solution of 790 parts (1 equivalent) of an alkylatedbenzenesulfonic acid and 71 parts of polybutenyl succinic anhydride(equivalent weight about 560) containing predominantly isobutene unitsin 176 parts of mineral oil is added 320 parts (8 equivalents) of sodiumhydroxide and 640 parts (20 equivalents) of methanol. The temperature ofthe mixture increases to 89° C. (reflux) over 10 minutes due toexotherming. During this period, the mixture is blown with carbondioxide at 4 cfh. (cubic feet/hr.). Carbonation is continued for about30 minutes as the temperature gradually decreases to 74° C. The methanoland other volatile materials are stripped from the carbonated mixture byblowing nitrogen through it at 2 cfh. while the temperature is slowlyincreased to 150° C. over 90 minutes. After stripping is completed, theremaining mixture is held at 155°-165° C. for about 30 minutes andfiltered to yield an oil solution of the desired basic sodium sulfonatehaving a metal ratio of about 7.75. This solution contains 12.4% oil.

Example S-2

Following the procedure of Example S-1, a solution of 780 parts (1equivalent) of an alkylated benzenesulfonic acid and 119 parts of thepolybutenyl succinic anhydride in 442 parts of mineral oil is mixed with800 parts (20 equivalents) of sodium hydroxide and 704 parts (22equivalents) of methanol. The mixture is blown with carbon dioxide at 7cfh. for 11 minutes as the temperature slowly increases to 97° C. Therate of carbon dioxide flow is reduced to 6 cfh. and the temperaturedecreases slowly to 88° C. over about 40 minutes. The rate of carbondioxide flow is reduced to 5 cfh. for about 35 minutes and thetemperature slowly decreases to 73° C. The volatile materials arestripped by blowing nitrogen through the carbonated mixture at 2 cfh.for 105 minutes as the temperature is slowly increased to 160° C. Afterstripping is completed, the mixture is held at 160° C. for an additional45 minutes and then filtered to yield an oil solution of the desiredbasic sodium sulfonate having a metal ratio of about 19.75. Thissolution contains 18.7% oil.

Example S-3

Following the procedure of Example S-1, a solution of 3120 parts (4equivalents) of an alkylated benzenesulfonic acid and 284 parts of thepolybutenyl succinic anhydride in 704 parts of mineral oil is mixed with1280 parts (32 equivalents) of sodium hydroxide and 2560 parts (80equivalents) of methanol. The mixture is blown with carbon dioxide at 10cfh. for 65 minutes as the temperature increases to 90° C. and thenslowly decreases to 70° C. The volatile material is stripped by blowingnitrogen at 2 cfh. for 2 hours as the temperature is slowly increased to160° C. After stripping is completed, the mixture is held at 160° C. for0.5 hour, and then filtered to yield an oil solution of the desiredbasic sodium sulfonate having a metal ratio of about 7.75. This solutioncontains 12.35% oil content.

Example S-4

Following the procedure of Example S-1, a solution of 3200 parts (4equivalents) of an alkylated benzenesulfonic acid and 284 parts of thepolybutenyl succinic anhydride in 623 parts of mineral oil is mixed with1280 parts (32 equivalents) of sodium hydroxide and 2560 parts (80equivalents) of methanol. The mixture is blown with carbon dioxide at 10cfh. for about 77 minutes. During this time the temperature increases to92° C. and then gradually drops to 73° C. The volatile materials arestripped by blowing with nitrogen gas at 2 cfh. for about 2 hours as thetemperature of the reaction mixture is slowly increased to 160° C. Thefinal traces of volatile material are vacuum stripped and the residue isheld at 170° C. and then filtered to yield a clear oil solution of thedesired sodium salt, having a metal ratio of about 7.72. This solutionhas an oil content of 11%.

Example S-5

Following the procedure of Example S-1, a solution of 780 parts (1equivalent) of an alkylated benzenesulfonic acid and 86 parts of thepolybutenyl succinic anhydride in 254 parts of mineral oil is mixed with480 parts (12 equivalents) of sodium hydroxide and 640 parts (20equivalents) of methanol. The reaction mixture is blown with carbondioxide at 6 cfh. for about 45 minutes. During this time the temperatureincreases to 95° C. and then gradually decreases to 74° C. The volatilematerial is stripped by blowing with nitrogen gas at 2 cfh. for aboutone hour as the temperature is increased to 160° C. After stripping iscomplete the mixture is held at 160° C. for 0.5 hour and then filteredto yield an oil solution of the desired sodium salt, having a metalratio of 11.8. The oil content of this solution is 14.7%.

Example S-6

Following the procedure of Example S-1, a solution of 3120 parts (4equivalents) of an alkylated benzenesulfonic acid and 344 parts of thepolybutenyl succinic anhydride in 1016 parts of mineral oil is mixedwith 1920 parts (48 equivalents) of sodium hydroxide and 2560 parts (80equivalents) of methanol. The mixture is blown with carbon dioxide at 10cfh. for about 2 hours. During this time the temperature increases to96° C. and then gradually drops to 74° C. The volatile materials arestripped by blowing with nitrogen gas at 2 cfh. for about 2 hours as thetemperature is increased from 74° C. to 160° C. by external heating. Thestripped mixture is heated for an additional hour at 160° C. andfiltered. The filtrate is vacuum stripped to remove a small amount ofwater, and again filtered to give a solution of the desired sodium salt,having a metal ratio of about 11.8. The oil content of this solution is14.7%.

Example S-7

Following the procedure of Example S-1, a solution of 2800 parts (3.5equivalents) of an alkylated benzenesulfonic acid and 302 parts of thepolybutenyl succinic anhydride in 818 parts of mineral oil is mixed with1680 parts (42 equivalents) of sodium hydroxide and 2240 parts (70equivalents) of methanol. The mixture is blown with carbon dioxide forabout 90 minutes at 10 cfh. During this period, the temperatureincreases to 96° C. and then slowly drops to 76° C. The volatilematerials are stripped by blowing with nitrogen at 2 cfh. as thetemperature is slowly increased from 76° C. to 165° C. by externalheating. Water is removed by vacuum stripping. Upon filtration, an oilsolution of the desired basic sodium salt is obtained. It has a metalratio of about 10.8 and the oil content is 13.6%.

Example S-8

Following the procedure of Example S-1, a solution of 780 parts (1equivalent) of an alkylated benzenesulfonic acid and 103 parts of thepolybutenyl succinic anhydride in 350 parts of mineral oil is mixed with640 parts (16 equivalents) of sodium hydroxide and 640 parts (20equivalents) of methanol. This mixture is blown with carbon dioxide forabout one hour at 6 cfh. During this period, the temperature increasesto 95° C. and then gradually decreases to 75° C. The volatile materialis stripped by blowing with nitrogen. During stripping, the temperatureinitially drops to 70° C. over 30 minutes and then slowly rises to 78°C. over 15 minutes. The mixture is then heated to 155° C. over 80minutes. The stripped mixture is heated for an additional 30 minutes at155°-160° C. and filtered. The filtrate is an oil solution of thedesired basic sodium sulfonate, having a metal ratio of about 15.2. Ithas an oil content of 17.1%.

Example S-9

A mixture of 584 parts (0.75 mole) of a commercial dialkyl aromaticsulfonic acid, 144 parts (0.37 mole) of a sulfurized tetrapropenylphenol prepared as in Example 3-C, 93 parts of a polybutenyl succinicanhydride as used in Example S-1, 500 parts of xylene and 549 parts ofoil is prepared and heated with stirring to 70° C. whereupon 97 parts ofpotassium hydroxide are added. The mixture is heated to 145° C. whileazeotroping water and xylene. Additional potassium hydroxide (368 parts)is added over 10 minutes and heating is continued at about 145°-150° C.whereupon the mixture is blown with carbon dioxide at 1.5 cfh. for about110 minutes. The volatile, materials are stripped by blowing withnitrogen and slowly increasing the temperature to about 160° C. Afterstripping, the reaction mixture is filtered to yield an oil solution ofthe desired potassium sulfonate having a metal ratio of about 10.Additional oil is added to the reaction product to provide an oilcontent of the final solution of 39%.

The following examples illustrate the preparation of neutral and basicalkaline earth metal salts (A-2-c).

Example S-10

A mixture of 906 parts of an oil solution of an alkyl phenyl sulfonicacid (having a number average molecular weight of 450, 564 parts mineraloil, 600 parts toluene, 98.7 parts magnesium oxide and 120 parts wateris blown with carbon dioxide at a temperature of 78°-85° C. for 7 hoursat a rate of about 3 cubic feet of carbon dioxide per hour. The reactionmixture is constantly agitated throughout the carbonation. Aftercarbonation, the reaction mixture is stripped to 165° C./20 tor and theresidue filtered. The filtrate is an oil solution (34% oil) of thedesired overbased magnesium sulfonate having a metal ratio of about 3.

Example S-11

A polyisobutenyl succinic anhydride is prepared by reacting achlorinated poly(isobutene) (having an average chlorine content of 4.3%and derived from a polyisobutene having a number average molecularweight of about 1150) with maleic anhydride at about 200° C. To amixture of 1246 parts of this succinic anhydride and 1000 parts oftoluene there is added at 25° C., 76.6 parts of barium oxide. Themixture is heated to 115° C. and 125 parts of water is added drop-wiseover a period of one hour. The mixture is then allowed to reflux at 150°C. until all the barium oxide is reacted. Stripping and filtrationcontaining the desired product.

Example S-12

A basic calcium sulfonate having a metal ratio of about 15 is preparedby carbonation, in increments, of a mixture of calcium hydroxide, aneutral sodium petroleum sulfonate, calcium chloride, methanol and analkyl phenol.

Example S-13

A mixture of 323 parts of mineral oil, 4.8 parts of water, 0.74 parts ofcalcium chloride, 79 parts of lime, and 128 parts of methyl alcohol isprepared, and warmed to a temperature of about 50° C. To this mixturethere is added 1000 parts of an alkyl phenyl sulfonic acid having anumber average molecular weight of 500 with mixing. The mixture then isblown with carbon dioxide at a temperature of about 50° C. at the rateof about 5.4 pounds per hour for about 2.5 hours. After carbonation, 102additional parts of oil are added and the mixture is stripped ofvolatile materials at a temperature of about 150°-155° C. at 55 mm.pressure. The residue is filtered and the filtrate is the desired oilsolution of the overbased calcium sulfonate having calcium content ofabout 3.7% and a metal ratio of about 1.7.

Example S-14

A mixture of 490 parts (by weight) of a mineral oil, 110 parts of water,61 parts of heptylphenol, 340 parts of barium mahogany sulfonate, and227 parts of barium oxide is heated at 100° C. for 0.5 hour and then to150° C. Carbon dioxide is then bubbled into the mixture until themixture is substantially neutral. The mixture is filtered and thefiltrate found to have a sulfate ash content of 25%.

Example S-15

A polyisobutene having a number average molecular weight of 50,000 ismixed with 10% by weight of phosphorus pentasulfide at 200° C. for 6hours. The resulting product is hydrolyzed by treatment with steam at160° C. to produce an acidic intermediate. The acidic intermediate isthen converted to a basic salt by mixing with twice its volume ofmineral oil, 2 moles of barium hydroxide and 0.7 mole of phenol andcarbonating the mixture at 150° C. to produce a fluid product.

The oil solutions (A-2) used in the process of this invention comprise amajor amount of hydrocarbon oil, minor amounts of at least one of thecarboxylic esters (A-2-a) and optionally at least one of the metal salts(A-2-b). The esters and metal salts may each be present in amounts offrom about 0.1 to about 20% by weight.

The oil solutions (A-2) also may contain other useful additivesincluding metal dihydrocarbyl dithiophosphates, viscosity improvers,including those having dispersant or detergent properties, compositionsgenerally referred to as friction modifiers when added to oils, etc.When included in the oil solution, these additives are present inamounts of from about 0.1 to about 20%, more generally from 0.1 to about10% by weight.

(A-2-d) Metal Dihydrocarbyl Dithiophosphate.

In another embodiment, the oil compositions of the present inventionalso contain (D) at least one metal dihydrocarbyl dithiophosphatecharacterized by the formula ##STR10## wherein R¹ and R² are eachindependently hydrocarbyl groups containing from 3 to about 13 carbonatoms, M is a metal, and n is an integer equal to the valence of M.

The oil solutions of the present invention may contain varying amountsof one or more of the above-identified metal dithiophosphates such asfrom about 0.01 to about 5% by weight based on the weight of the totaloil solutions.

The hydrocarbyl groups R¹ and R² in the dithiophosphate of Formula XImay be alkyl, cycloalkyl, aralkyl or alkaryl groups, or a substantiallyhydrocarbon group of similar structure. By "substantially hydrocarbon"is meant hydrocarbons which contain substituent groups such as ether,ester, nitro, or halogen which do not materially affect the hydrocarboncharacter of the group.

Illustrative alkyl groups include isopropyl, isobutyl, n-butyl,sec-butyl, the various amyl groups, n-hexyl, methylisobutyl carbinyl,heptyl, 2-ethylhexyl, diisobutyl, isooctyl, nonyl, behenyl, decyl,dodecyl, tridecyl, etc. Illustrative alkylphenyl groups includebutylphenyl, amylphenyl, heptylphenyl, butylene dimer-substitutedphenol, propylene tetramer-substituted phenol, etc. Cycloalkyl groupslikewise are useful and these include chiefly cyclohexyl and the loweralkylcyclohexyl radicals. Many substituted hydrocarbon groups may alsobe used, e.g., chloropentyl, dichlorophenyl, and dichlorodecyl.

The phosphorodithioic acids from which the metal salts useful in thisinvention are prepared are well known. Examples of dihydrocarbylphosphorodithioic acids and metal salts, and processes for preparingsuch acids and salts are found in, for example, U.S. Pat. Nos.4,263,150; 4,289,635; 4,308,154; and 4,417,990. These patents are herebyincorporated by reference for such disclosures.

The phosphorodithioic acids are prepared by the reaction of phosphoruspentasulfide with an alcohol or phenol or mixtures of alcohols. Thereaction involves four moles of the alcohol or phenol per mole ofphosphorus pentasulfide, and may be carried out within the temperaturerange from about 50° C. to about 200° C. Thus the preparation ofO,O-di-n-hexyl phosphorodithioic acid involves the reaction ofphosphorus pentasulfide with four moles of n-hexyl alcohol at about 100°C. for about two hours. Hydrogen sulfide is liberated and the residue isthe defined acid. The preparation of the metal salt of this acid may beeffected by reaction with metal oxide. Simply mixing and heating thesetwo reactants is sufficient to cause the reaction to take place and theresulting product is sufficiently pure for the purposes of thisinvention.

The metal salts of dihydrocarbyl dithiophosphates which are useful inthis invention include those salts containing Group I metals, Group IImetals, aluminum, lead, tin, molybdenum, manganese, iron, cobalt, andnickel. The Group II metals, aluminum, iron, tin, iron, cobalt, lead,molybdenum, manganese, nickel and copper are among the preferred metals.Zinc and copper are especially useful metals.

The oil solutions useful in the present invention also may contain atleast one of the materials referred to as friction modifiers in thelubricant art. Various amines, particularly tertiary amines areeffective friction modifiers. Examples of tertiary amine frictionmodifiers include N-fatty alkyl-N,N-diethanol amines, N-fattyalkyl-N,N-diethoxy ethanol amines, etc. Such tertiary amines can beprepared by reacting a fatty alkyl amine with an appropriate number ofmoles of ethylene oxide. Tertiary amines derived from naturallyoccurring substances such as coconut oil and oleoamine are availablefrom Armour Chemical Company under the trade designation "Ethomeen".Particular examples are the Ethomeen-C and the Ethomeen-O series.

Sulfur-containing compounds such as sulfurized C₁₂₋₂₄ fats, alkylsulfides and polysulfides wherein the alkyl groups contain from 1 to 8carbon atoms, and sulfurized polyolefins also may be included in the oilsolutions of the invention. Partial fatty acid esters of polyhydricalcohols, also may be included in the oil solutions used in theinvention in amounts of up to about 5 or 10% by weight. The hydroxyfatty acid esters are selected from hydroxy fatty acid esters ofdihydric or polyhydric alcohols or oil-soluble oxyalkylenatedderivatives thereof.

The term "fatty acid" as used in the specification and claims refers toacids which may be obtained by the hydrolysis of a naturally occurringvegetable or animal fat or oil. These acids usually contain from about 8to about 22 carbon atoms and include, for example, caprylic acid,caproic acid, palmitic acid, stearic acid, oleic acid, linoleic acid,etc. Acids containing from 10 to 22 carbon atoms generally arepreferred, and in some embodiments, those acids containing from 16 to 18carbon atoms are especially preferred.

The polyhydric alcohols which can be utilized in the preparation of thepartial fatty acids contain from 2 to about 8 or 10 hydroxyl groups,more generally from about 2 to about 4 hydroxyl groups. Examples ofsuitable polyhydric alcohols include ethylene glycol, propylene glycol,neopentylene glycol, glycerol, pentaerythritol, etc. Ethylene glycol andglycerol are preferred. Polyhydric alcohols containing lower alkoxygroups such as methoxy and/or ethoxy groups may be utilized in thepreparation of the partial fatty acid esters.

Suitable partial fatty acid esters of polyhydric alcohols include, forexample, glycol monoesters, glycerol mono- and diesters, andpentaerythritol di- and/or triesters. The partial fatty acid esters ofglycerol are preferred, and of the glycerol esters, monoesters, ormixtures of monoesters and diesters are often utilized. The partialfatty acid esters of polyhydric alcohols can be prepared by methods wellknown in the art, such as by direct esterification of an acid with apolyol, reaction of a fatty acid with an epoxide, etc.

It is generally preferred that the partial fatty acid ester containolefinic unsaturation, and this olefinic unsaturation usually is foundin the acid moiety of the ester. In addition to natural fatty acidscontaining olefinic unsaturation such as oleic acid, octeneoic acids,tetradeceneoic acids, etc., can be utilized in forming the esters.

The partial fatty acid esters utilized in the oil solutions of thepresent invention may be present as components of a mixture containing avariety of other components such as unreacted fatty acid, fullyesterified polyhydric alcohols, and other materials. Commerciallyavailable partial fatty acid esters often are mixtures which contain oneor more of these components as well as mixtures of mono- and diesters ofglycerol.

One method for preparing monoglycerides of fatty acids from fats andoils is described in Birnbaum U.S. Pat. No. 2,875,221. The processdescribed in this patent is a continuous process for reacting glyceroland fats to provide a product having a high proportion of monoglyceride.Among the commercially available glycerol esters are ester mixturescontaining at least about 30% by weight of monoester and generally fromabout 35% to about 65% by weight of monoester, about 30% to about 50% byweight of diester, and the balance in the aggregate, generally less thanabout 15%, is a mixture of triester, free fatty acid and othercomponents. Specific examples of commercially available materialcomprising fatty acid esters of glycerol include Emery 2421 (EmeryIndustries, Inc.), Cap City GMO (Capital), DUR-EM 114, DUR-EM GMO, etc.(Durkee Industrial Foods, Inc.) and various materials identified underthe mark MAZOL GMO (Mazer Chemicals, Inc.). Other examples of partialfatty acid esters of polyhydric alcohols may be found in K. S. Markley,Ed., Fatty Acids, Second Edition, Parts I and V, Interscience Publishers(1968). Numerous commercially available fatty acid esters of polyhydricalcohols are listed by tradename and manufacturer in McCutcheonEmulsifiers and Detergents, North American and International CombinedEditions (1981).

Viscosity improvers can also be included in the oil solutions (A-2) usedin the invention. A number of types of viscosity improvers are known inthe art, and many of these are described in Ranney, Lubricant Additives,(Noyes Data Corporation, 1973), pp. 93-119. Illustrative viscosityimprovers include various olefin polymers such as polybutene (especiallycontaining predominantly isobutene units); ethylene-propylenecopolymers; copolymers of ethylene and other low molecular weightolefins (especially alpha-olefins); terpolymers of ethylene; propyleneand various dienes (especially non-conjugated dienes); polybutadiene;hydrogenated styrene-butadiene copolymers; alkylated polystyrenes;polymers of alkyl methacrylates; alkylene polyethers; and polyestersprepared from polyols, short-chain dicarboxylic acids and monobasiccarboxylic acid terminators (useful predominantly in lubricants in whichthe lubricating oil is a synthetic ester).

One type of viscosity improver having dispersant or detergent propertiescomprises interpolymers being substantially free of titratable acidityand containing carboxylic ester groups in which part of the alcoholmoieties have at least 8 aliphatic carbon atoms and another part have nomore than 7 aliphatic carbon atoms, and also containingcarbonyl-polyamino groups in which the polyamino group is derived from acompound having one primary or secondary amino group. These polymers aredescribed in U.S. Pat. No. 3,702,300, which is incorporated by referencefor such description. Preferred are interpolymers prepared by firstcopolymerizing styrene with maleic anhydride and subsequentlyesterifying a portion of the carboxylic acid groups with a mixture ofprimary alcohols having the numbers of carbon atoms noted above, andneutralizing the remaining carboxylic acid groups with a suitable amine.The working examples of U.S. Pat. No. 3,702,300 illustrate specificsuitable polymers.

Isocyanate momoners are recovered from crude isocyanate concentratesobtained in the production of isocyanates in accordance with the processof the present invention by heating a mixture of the crude isocyanateconcentrate and the above-described oil solutions at an elevatedtemperature whereby the isocyanate monomer is distilled from theconcentrate and recovered. The residue is a liquid which can be removedeasily from the heating apparatus and can be disposed of by burning. Ifthe oil solution is not added to the isocyanate concentrate, the residuewhich is obtained after distillation of the isocynanate from theconcentrate is a slag-like residue which is an extremely hard solidsubstantially insoluble in all conventional solvents. The slag-likesolid is difficult to remove from the distillation apparatus, and whenremoved from the apparatus, presents significant disposal problems.

The incorporation of the oil solutions described above into theisocyanate concentrate prior to distillation also facilitates thedistillation process resulting in an increase in the yield ofdistillate, and the distillation can generally be effected at lowertemperatures than when the distillation is conducted in the absence ofthe oil solutions.

The oil solutions (A-2) of the present invention can be mixed with theisocyanate concentrates in any amount, but for practical and economicreasons, the mixtures which are subject to distillation generally willcontain from about 70 to about 99 parts by weight of the isocyanateconcentrate (A-1) and from about 1 to about 30 parts by weight of theoil solution (A-2). More particularly, desirable results are obtainedwith up to about 20 parts by weight of the oil solution in 80 or moreparts of the isocyanate concentrate.

The oil solutions (A-2) will comprise a major amount of the hydrocarbonoil (A-2-a) and minor amounts of the carboxylic esters (A-2-b) and/orthe neutral or basic metal salts (A-2-c) described above. In particularembodiments, the oil solutions will contain from about 0.1 to about 20%by weight of the carboxylic esters (A-2-b) and from about 0.1 to about20% by weight of at least one metal salt (A-2-c). In another embodiment,the oil solution also contains at least one metal salt of adihydrocarbyldithiophosphoric acid (A-2-d), and the amount of said saltmay range from about 0.1 to about 10% by weight. The other additivesdescribed above as being optional also may be included in the oilsolutions (A-2).

Distillation of the mixture of crude isocyanate concentrate and oilsolution is effected by heating the mixture to an elevated temperaturesufficient to distil the isocyanate monomer from the mixture. Tofacilitate the distillation and reduce the temperature, the distillationpreferably is accomplished at reduced pressure. The distillationtemperature is regulated to provide for effective distillation of theisocyanate monomer without distillation of any of the other componentsof the mixture. Thus, the hydrocarbon oil (A-2-a) used in the oilsolution, and any other solvents included in the components of the oilsolution should have initial boiling points below the boiling point ofthe isocyanate monomer in the concentrate. Thus, in one embodiment, ahydrocarbon oil utilized in the formation of mixtures comprising crudetolylene diisocyanate concentrates is characterized as having an initialboiling point of at least about 200° C. at 10 mm. Hg. The boiling pointof the tolylene diisocyanates is about 125° C. at 10 mm. Hg.

The following examples illustrate the oil solutions useful in thepresent invention.

    ______________________________________                                        Oil Solution (A)    Parts/Wt.                                                 ______________________________________                                        Example 1                                                                     Citgo 350 Neutral oil                                                                             94                                                        (boiling point 660° F.)                                                Carboxylic ester of Ex. E-1                                                                       5                                                         Basic sodium sulfonate of                                                                         1                                                         Ex. S-1                                                                       Example 2                                                                     Mineral oil (Citgo 350                                                                            90                                                        Neutral)                                                                      Carboxylic ester of Ex. E-1                                                                       5                                                         Sodium salt of Ex. S-2                                                                            4.0                                                       Zinc dithiophosphate prepared                                                                     1.0                                                       from propylene tetramer-                                                      substituted phenol (containing                                                3.6% zinc, 3.2% phosphorus                                                    and 27% oil)                                                                  Example 3                                                                     Citgo 350 Neutral oil                                                                             94                                                        Carboxylic ester of Ex. E-12                                                                      5                                                         Basic calcium alkylated                                                                           1                                                         benzene sulfonate (44% oil,                                                   15.5% calcium and metal                                                       ratio of 20)                                                                  Example 4                                                                     Mineral oil (Citgo 350                                                                            90                                                        Neutral)                                                                      Carboxylic ester of Ex. E-12                                                                      5                                                         Sodium salt of Ex. S-2                                                                            4                                                         Basic calcium alkylated                                                                           1                                                         benzene sulfonate (44% oil,                                                   15.5% calcium and metal                                                       ratio of 20)                                                                  Example 5                                                                     Citgo 350 Neutral oil                                                                             94                                                        Carboxylic ester of Ex. E-12                                                                      5                                                         Basic magnesium alkylated                                                                         1                                                         benzene sulfonate (32% oil,                                                   metal ratio of 14.7)                                                          Example 6                                                                     Citgo 350 Neutral oil                                                                             90                                                        Carboxylic ester of Ex. E-12                                                                      5                                                         Basic calcium alkylated                                                                           4                                                         benzene sulfonate (44% oil,                                                   15.5% calcium and metal                                                       ratio of 20)                                                                  Zinc dithiophosphate prepared                                                                     1                                                         from propylene tetramer-                                                      substituted phenol (containing                                                3.6% zinc, 3.2% phosphorus                                                    and 27% oil)                                                                  ______________________________________                                    

The process of the present invention is illustrated by the followingexamples.

Example A

A mixture comprising 85 parts of a concentrate ofhexamethylene-1,6-diisocyanate obtained by the reaction of hexamethylenediamine with phosgene, and 15 parts of the oil solution of Example 1 ischarged to a distillation apparatus, and the mixture is heated to atemperature of about 130° C. at 10 mm. Thehexamethylene-1,6-diisocyanate distills from the mixture and iscollection. When the rate of distillation becomes negligible, theresidue in the reaction vessel is cooled and is recovered as a liquid.

Example B

The process of Example A is repeated except that the isocyanateconcentrate is mixed with 15 parts of the solution of Example 3.

Example C

The procedure of Example A is repeated except that the concentrate usedin this example is a tolylene diisocyanate concentrate obtained byphosgenation of 2,4-diamino toluene.

Example D

The procedure of Example A is repeated except that the isocyanateconcentrate is a tolylene diisocyanate mixture obtained by phosgenationof a mixture comprising 80 parts of 2,4-diamino toluene and 20 parts of2,6-diamino toluene.

Example E

The procedure of Example A is repeated except that the isocyanateconcentrate is a concentrate obtained by reaction of 1 mole of2,4-diamino toluene with 2 moles of phosgene, and the oil solution isthe solution of Example 3.

Example F

The procedure of Example E is repeated except that the oil solution usedis the solution of Example 6.

While the invention has been explained in relation to its preferredembodiments, it is to be understood that various modifications thereofwill become apparent to those skilled in the art upon reading thespecification. Therefore, it is to be understood that the inventiondisclosed herein is intended to cover such modifications as fall withinthe scope of the appended claims.

I claim:
 1. A process for the separation and recovery of isocyanatemonomers from isocyanate concentrates formed in the production ofisocyanates and comprising a volatile isocyanate monomer and by-productswhich comprises the steps of:(A) preparing a mixture comprising(A-1) theisocyanate concentrate; and (A-2) an oil solution comprising;(A-2-a) amajor amount of hydrocarbon oil, and (A-2-b) a minor amount of at leastone carboxylic ester obtained by reacting(A-2-b-1) at least onesubstituted succinic acylating agent with (A-2-b-2) at least one alcoholof the general formula

    R.sub.3 (OH).sub.m                                         (I)

wherein R₃ is a monovalent or polyvalent organic group joined to the OHgroups through a carbon bonds, and m is an integer of from 1 to about10; and (B) heating the mixture to an elevated temperature wherebyisocyanate monomer is distilled and recovered leaving a liquid residue.2. The process of claim 1 wherein the mixture prepared in step (A)comprises from about 70 to about 99 parts by weight of the isocyanateconcentrate (A-1) and from about 1 to 30 parts by weight of the oilsolution
 3. The process of claim 1 wherein the hydrocarbon oil (A-2-a)is a lubricating oil or a fuel oil having an initial boiling point of atleast about 200° C. at 10 mm. Hg.
 4. The process of claim 1 wherein theisocyanate concentrate is obtained by reacting aliphatic,cycloaliphatic, aromatic or mixed aliphatic-aromatic amines withphosgene.
 5. The process of claim 1 wherein the isocyanate concentrateis obtained by reacting an aromatic diamine with phosgene.
 6. Theprocess of claim 1 wherein the isocyanate concentrate is a concentratecomprising 2,4- or 2,6-tolylenediisocyanate.
 7. The process of claim 1wherein the oil solution (A-2) comprises at least about 70% by weight ofthe hydrocarbon oil.
 8. The process of claim 1 wherein the oil solution(A-2) comprises from about 0.1 to about 20% by weight of at least onecarboxylic ester (A-2-b).
 9. The process of claim 1 wherein the oilsolution (A-2) also contains(A-2-c) a minor amount of at least oneneutral or basic alkali metal or alkaline earth metal salt of at leastone acidic organic compound.
 10. The process of claim 9 wherein the oilsolution (A-2) contains from about 0.1 to about 20% by weight of atleast one metal salt (A-2-c).
 11. The process of claim 1 wherein thesubstituted succinic ester acylating agent (A-2-b-1) consists ofsubstituent groups and succinic groups wherein the substituent groupsare derived from a polyalkene.
 12. The process of claim 11 wherein thesubstituent groups are derived from one or more polyalkenes selectedfrom the group consisting of homopolymers and interpolymers of terminalolefins of from 2 to about 16 carbon atoms with the proviso that saidinterpolymers can optionally contain up to about 25% of polymer unitsderived from internal olefins of up to 6 carbon atoms.
 13. The processof claim 11 wherein the substituent groups are derived from a memberselected from the group consisting of polybutene, ethylene-propylenecopolymer, polypropylene, and mixtures of two or more of any of these.14. The process of claim 11 wherein the substituent group contains atleast about 8 carbon atoms.
 15. The process of claim 11 wherein thesubstituent groups have a number average molecular weight of at leastabout
 700. 16. The process of claim 1 wherein the alcohol of Formula Iis neopentyl alcohol, ethylene glycol, glycerol, pentaerythritol,sorbitol, mono-alkyl or monoaryl ethers of a poly(oxyalkylene)glycol, ormixtures of any of these.
 17. The process of claim 1 wherein thesubstituted succinic acylating agent (A-2-b-1) consists of substituentgroups and succinic groups wherein the substituent groups are derivedfrom a polyalkene, said polyalkene being characterized by an Mn value ofabout 1300 to about 5000 and an Mw/Mn value of from about 1.5 to about4.5, said acylating agents being characterized by the presence withintheir structure of at least about 1.3 succinic groups for eachequivalent weight of substituent group.
 18. The process of claim 1wherein the carboxylic ester (A-2-b) prepared by reacting the acylatingagent with the alcohol is further reacted with (A-2-b-3) at least oneamine containing at least one HN< group.
 19. The process of claim 18wherein the amine is an alkylene polyamine.
 20. The process of claim 9wherein the acidic organic compound of (A-2-c) is a sulfur acid,carboxylic acid, phosphorus acid, phenol, or mixtures thereof.
 21. Theprocess of claim 9 wherein the acidic organic compound of (A-2-c) is atleast one organic sulfonic or carboxylic acid.
 22. The process of claim9 wherein the metal salt (A-2-c) is at least one neutral or basicalkaline earth metal salt of an organic carboxylic or sulfonic acid. 23.The process of claim 1 wherein the oil solution (A-2) also contains(A-2-d) a minor amount of at least one metal salt of adihydrocarbyldithiophosphoric acid wherein the metal is a Group IImetal, aluminum, tin, iron, cobalt, lead, molybdenum, manganese, nickelor copper.
 24. The process of claim 23 wherein the metal salt is a zincsalt.
 25. The process of claim 1 wherein the mixture is heated in step(B) to an elevated temperature under reduced pressure which is effectiveto distill the isocyanate monomer from the mixture prepared in step (A).26. A process for the separation and recovery of isocyanate monomersfrom isocyanate concentrates obtained by reacting aliphatic,cycloaliphatic, aromatic or mixed aliphatic-aromatic amines withphosgene, and comprising a volatile isocyanate monomer and by-productswhich comprises the steps of:(A) preparing a mixture comprising(A-1) atleast about 70% by weight of the isocyanate concentrate; and (A-2) fromabout 1 to about 30% by weight of an oil solution comprising;(A-2-a) amajor amount of hydrocarbon oil having a boiling point above the boilingpoint of the isocyanate monomer; (A-2-b) a minor amount of at least onecarboxylic ester obtained by reacting(A-2-b-1) at least one substitutedsuccinic acylating agent with (A-2-b-2) at least one alcohol of thegeneral formula

    R.sub.3 (OH).sub.m                                         (I)

wherein R₃ is a monovalent or polyvalent organic group joined to the OHgroups through carbon bonds, and m is an integer of from 1 to about 10;and (A-2-c) a minor amount of at least one neutral or basic alkali metalor alkaline earth metal salt of at least one acidic organic compound;and (B) heating the mixture to an elevated temperature wherebyisocyanate monomer is distilled and recovered leaving a liquid residue.27. The process of claim 26 wherein the hydrocarbon oil (A-2-a) is alubricating oil or a fuel oil having an initial boiling point of atleast about 200° C. at 10 mm. Hg.
 28. The process of claim 26 whereinthe isocyanate concentrate is obtained by reacting an aromatic aminewith phosgene.
 29. The process of claim 26 wherein the isocyanateconcentrate is a concentrate comprising 2,4- or2,6-tolylenediisocyanate.
 30. The process of claim 26 wherein the oilsolution (A-2) comprises from about 0.1 to about 20% by weight of atleast one carboxylic ester (A-2-b) and from about 0.1 to about 20% byweight of at least one metal salt (A-2-c).
 31. The process of claim 26wherein the substituted succinic ester acylating agent (A-2-b-1)consists of substituent groups and succinic groups wherein thesubstituent groups are derived from a polyalkene containing at least 8carbon atoms.
 32. The process of claim 31 wherein the substituent groupsare derived from a member selected from the group consisting ofpolybutene, ethylene-propylene copolymer, polypropylene, and mixtures oftwo or more of any of these.
 33. The process of claim 31 wherein thesubstituent groups have a number average molecular weight of at leastabout
 700. 34. The process of claim 26 wherein the alcohol of Formula Iis neopentyl alcohol, ethylene glycol, glycerol, pentaerythritol,sorbitol, mono-alkyl or monoaryl ethers of a poly(oxyalkylene)glycol, ormixtures of any of these.
 35. The process of claim 26 wherein thesubstituted succinic acylating agent (A-2-b-1) consists of substituentgroups and succinic groups wherein the substituent groups are derivedfrom a polyalkene, said polyalkene being characterized by an Mn value ofabout 1300 to about 5000 and an Mw/Mn value of from about 1.5 to about4.5, said acylating agents being characterized by the presence withintheir structure of at least about 1.3 succinic groups for eachequivalent weight of substituent group.
 36. The process of claim 26wherein the carboxylic ester (A-2-b) prepared by reacting the acylatingagent with the alcohol is further reacted with (A-2-b-3) at least oneamine containing at least one HN< group.
 37. The process of claim 36wherein the amine is an alkylene polyamine.
 38. The process of claim 26wherein the acidic organic compound of (A-2-c) is a sulfur acid,carboxylic acid, phosphorus acid, phenol, or mixtures thereof.
 39. Theprocess of claim 26 wherein the acidic organic compound of (A-2-c) is atleast one organic sulfonic or carboxylic acid.
 40. The process of claim26 wherein the metal salt (A-2-c) is at least one neutral or basicalkaline earth metal salt of an organic carboxylic or sulfonic acid. 41.The process of claim 26 wherein the oil solution (A-2) also contains(A-2-d) a minor amount of (A-2-d) at least one metal salt of adihydrocarbyldithiophosphoric acid wherein the metal is a Group IImetal, aluminum, tin, iron, cobalt, lead, molybdenum, manganese, nickelor copper.
 42. The process of claim 41 wherein the metal salt is a zincsalt.
 43. A process for the separation and recovery of tolylenediisocyanate monomer from tolylene diisocyanate concentrates which areobtained from the reaction of diaminotoluene with phosgene whichcomprises the steps of:(A) preparing a mixture of(A-1) a major amount ofthe isocyanate concentrate; and (A-2) a minor amount of an oil solutioncomprising(A-2-a) a major amount of a hydrocarbon oil; (A-2-b) fromabout 0.1 to about 20% by weight of at least one carboxylic esterobtained by reacting(A-2-b-1) at least one substituted succinicacylating agent with (A-2-b-2) at least one polyhydric alcohol of thegeneral formula

    R.sub.3 (OH).sub.m                                         (I)

wherein R₃ is a monovalent or polyvalent organic group joined to the OHgroups through carbon atoms, and m is an integer of from 2 to about 10;and(A-2-c) from about 0.1 to about 20% by weight of at least one neutralor basic alkali metal or alkaline earth metal salt of at least oneorganic carboxylic or sulfonic acid; and (B) heating the mixtureprepared in (A) to an elevated temperature at a reduced pressure wherebytolylene diisocyanate monomer is removed by distillation and recoveredleaving a liquid residue.
 44. The process of claim 43 wherein thediaminotoluene reacted with phosgene is 2,4-diaminotoluene,2,6-diaminotoluene, or mixtures thereof.
 45. The process of claim 43wherein the hydrocarbon oil (A-2-a) is a lubricating oil or a fuel oilhaving a boiling point of at least about 200° C. at 10 mm. Hg.
 46. Theprocess of claim 43 wherein the oil solution (A-2) comprises at leastabout 70% by weight of the hydrocarbon oil.
 47. The process of claim 43wherein the substituted succinic ester acylating agent (A-2-b-1)consists of substituent groups and succinic groups wherein thesubstituent groups are derived from a polyalkene characterized as havinga number average molecular weight of at least
 700. 48. The process ofclaim 47 wherein the substituent groups are derived from a memberselected from the group consisting of polybutene, ethylene-propylenecopolymer, polypropylene, and mixtures of two or more of any of these.49. The process of claim 43 wherein the alcohol of Formula I isneopentyl alcohol, ethylene glycol, glycerol, pentaerythritol, sorbitol,mono-alkyl or monoaryl ethers of a poly(oxyalkylene)glycol, or mixturesof any of these.
 50. The process of claim 43 wherein the substitutedsuccinic acylating agent (A-2-b-1) consists of substituent groups andsuccinic groups wherein the substituent groups are derived from apolyalkene, said polyalkene being characterized by an Mn value of about1300 to about 5000 and an Mw/Mn value of from about 1.5 to about 4.5,said acylating agents being characterized by the presence within theirstructure of at least about 1.3 succinic groups for each equivalentweight of substituent group.
 51. The process of claim 43 wherein theacidic organic compound of (A-2-c) is at least one organic sulfonicacid.
 52. The process of claim 43 wherein the metal salt (A-2-c) is atleast one neutral or basic alkaline earth metal salt of an organiccarboxylic or sulfonic acid.
 53. The process of claim 43 wherein the oilsolution (A-2) also contains (A-2-d) a minor amount of at least onemetal salt of a dihydrocarbyldithiophosphoric acid wherein the metal isa Group II metal, aluminum, tin, iron, cobalt, lead, molybdenum,manganese, nickel or copper.
 54. The process of claim 53 wherein themetal salt is a zinc salt.
 55. The process of claim 43 wherein themixture is heated in step (B) to an elevated temperature under reducedpressure which is effective to distill the isocyanate monomer from themixture prepared in step (A).